v0.2.8

.env.example

@@ -20,7 +20,7 @@ SIEVE_ALLOW_INSECURE_AUTH=false
 SIEVE_TIMEOUT_SECS=10
 
 TRUSTED_PROXIES=127.0.0.1,::1
-RUST_LOG=info
+RUST_LOG=warn,rustbox=debug,tower_http=info
 # RUSTBOX_CONFIG=/etc/rustbox/rustbox.toml
 
 # RustBox 0.2 storage/search nested overrides use double underscores.

CHANGELOG.md

@@ -1,5 +1,36 @@
 # RustBox changelog
 
+### 0.2.8
+
+- Scoped default logging so RustBox can run at DEBUG/INFO without enabling verbose dependency logs; Tantivy merge/GC/file-watcher noise and its internal filesystem/source paths are hidden unless explicitly enabled through a custom `RUST_LOG` target filter. Development and deployment examples now use target-scoped filters.
+- Kept administrator diagnostics process-local and cross-platform: removed host CPU/RAM/load-average and Linux `/proc` sampling; runtime diagnostics now rely on portable RustBox in-memory counters plus the process PID.
+- Added a disabled-by-default administrator system-diagnostics endpoint with loopback-only CIDR allowlisting, mandatory token or Basic authentication, fail-closed trusted-proxy handling, secret redaction, live SQL/session/storage/search probes, active IMAP IDLE/session/runtime state and bounded security telemetry for failed logins, rate limiting, access denials and server errors.
+- Moved the synchronization/index activity indicator to the left of Contacts.
+- Corrected production TOML section ordering so intended top-level database/session/mail/security/special-folder settings are no longer accidentally parsed as search settings.
+- Refined folder counters so only the unread value is emphasized, hid the sync/index activity icon when idle, and made manual search-index rebuilds drive the same live activity indicator as background indexing.
+- Made folder totals/unread counts server-authoritative: IMAP `STATUS MESSAGES/UNSEEN` drives badges, selected-mailbox fallback counts `UID SEARCH UNSEEN`, periodic reconciliation repairs counters even when `HIGHESTMODSEQ` is unchanged, and mutation-time compare-and-set/retry prevents out-of-order STATUS responses from rolling counters backwards.
+- Decoupled counter refresh from folder-tree discovery: a forced counter refresh reuses a fresh cached folder tree and batches STATUS requests instead of forcing another IMAP LIST.
+- Changed read/unread/flag updates to patch the affected message row and folder badge live; ordinary flag changes no longer rebuild the message list, removing the reader/list jump during mark-read operations.
+- Added responsive folder counters (`total / unread` when unread is non-zero, total-only at zero, compact mode in narrow sidebars) and surfaced IMAP header-cache plus search-index backlog in the top-right activity indicator/tooltip.
+- Extended the opt-in security-header middleware with a private `/api` profile (`no-store`, `nosniff`, same-origin CORP, `frame-ancestors 'none'` and `X-Frame-Options: DENY`), while keeping Permissions-Policy/COOP and the full document CSP on HTML and HSTS at the public HTTPS edge; disabling `security_headers_enabled` removes the whole RustBox-added security profile.
+- Minimized unauthenticated `/api/auth/policy` to `rememberMeEnabled`; optional feature policy moved behind authenticated `/api/auth/session-policy`, and session/remember durations are no longer exposed by policy endpoints.
+- Added optimistic read/unread updates in the browser with guarded rollback, followed by authoritative server reconciliation; normal read/unread operations no longer replace the message list.
+- Fixed realtime WebSocket deduplication so unique server `eventId` values always win over payload fingerprints; rapid legitimate counter cycles such as `1 → 0 → 1` are no longer dropped as duplicates. Active-folder total text is patched live together with the sidebar counter.
+- Hardened IDLE/CONDSTORE reconciliation: counter STATUS no longer advances the flag-sync cursor, non-CONDSTORE servers fall back to a full `UID FLAGS` comparison, partial IMAP fetch streams are discarded instead of being treated as complete, and IDLE header/index writes participate in the same cache-generation transaction.
+- Fixed UIDVALIDITY reset writes to stay inside the same database transaction on SQLite, MySQL and PostgreSQL instead of mixing transaction/base-connection writes.
+- Tightened the HTML CSP to `style-src 'self'` plus the narrower `style-src-attr 'unsafe-inline'`; inline JavaScript remains disallowed.
+- Added regression coverage for authoritative unread refresh, API/document/static header profiles and pre-login policy minimization.
+- Added database migration V048 on SQLite, MySQL and PostgreSQL: folder counters now carry a monotonic `counter_generation`, so delayed STATUS responses cannot win an ABA race after newer read/unread activity. V049 is the next migration number.
+- Bumped the application/source release to 0.2.8.
+
+### 0.2.7
+- Made opt-in browser security headers content-type-aware instead of attaching document-only policies to every response.
+- HTML documents keep the full CSP, clickjacking, permissions, COOP, referrer and MIME-sniffing protections.
+- CSS responses now receive only the applicable `Referrer-Policy` and `X-Content-Type-Options`; JavaScript, JSON, SVG, API and other non-document responses retain `X-Content-Type-Options: nosniff` without redundant document policies.
+- Added regression coverage for HTML, CSS and API header sets while preserving the disabled-by-default compatibility switch.
+- No schema migration is required; runtime schema remains V047 and V048 remains the next migration number.
+- Bumped the application/source release to 0.2.7.
+
 ### 0.2.6
 - Fixed iPhone/iOS reader toolbar popovers (`Message details` and `Move / copy`) by rendering the open menu outside the horizontally scrolling toolbar and positioning it against the visual viewport.
 - Made folder counters and message-list refreshes more responsive: realtime sync stores the server-reported unread count, folder hierarchy refresh avoids unnecessary IMAP LIST calls, and manual refresh forces the active-folder status check in parallel with counter refresh.

Cargo.lock

@@ -3506,7 +3506,7 @@ dependencies = [
 
 [[package]]
 name = "rustbox"
-version = "0.2.6"
+version = "0.2.8"
 dependencies = [
  "aes-gcm",
  "async-imap",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rustbox"
-version = "0.2.6"
+version = "0.2.8"
 edition = "2024"
 rust-version = "1.99.1"
 default-run = "rustbox"

NOTICE.md

@@ -1,6 +1,6 @@
 # RustBox attribution / notice
 
-RustBox 0.2.6 is derived from the Oxi webmail project:
+RustBox 0.2.8 is derived from the Oxi webmail project:
 
 - Upstream: `c0h1b4/oxi`
 - Base snapshot: `7f1507c486b78cf33e54beb701dd460d3bd2bd5d`

README.md

@@ -1,4 +1,4 @@
-# RustBox 0.2.6
+# RustBox 0.2.8
 
 RustBox is a webmail derived from `c0h1b4/oxi`. The consumed Oxi revision is recorded in `UPSTREAM_BASE`.
 
@@ -34,7 +34,7 @@ rustbox/
 
 `build.rs` combines the CSS modules from `src/web/css/manifest.txt` and JavaScript modules from `src/web/js/manifest.txt`. Cargo embeds the generated CSS/JS bundles, HTML and SVG sprite in the RustBox executable. There is no standalone source `src/web/app.js`; `src/web/` is the single source of truth and Cargo generates the embedded bundles in `OUT_DIR`.
 
-## Storage and search in 0.2.6
+## Storage and search in 0.2.8
 
 RustBox separates three concerns: SQL metadata, blob storage and search. The SQL engine does **not** decide whether `data_dir` may be used. A single-node PostgreSQL/MySQL deployment may still use filesystem blobs and local Tantivy. In cluster mode, local node state is rejected unless the configured backend is explicitly shared.
 
@@ -51,6 +51,8 @@ Search backends:
 
 In a cluster using shared SQL + S3/shared POSIX + OpenSearch/disabled search + `pgp_enabled=false`, `data_dir` is not required as persistent node state. See `docker/README.md` for ready Compose variants.
 
+Administrator-only deep runtime diagnostics can be enabled separately under `[diagnostics_endpoint]`. It is disabled and loopback-only by default, supports a network allowlist plus token or Basic Auth, redacts secrets, and probes SQL/Redis/storage/search/session/runtime/security state. See [`docs/SYSTEM_DIAGNOSTICS.md`](docs/SYSTEM_DIAGNOSTICS.md).
+
 ## Configure mail servers
 
 Mail endpoints are configured by the administrator, not on the login screen. Users enter only email and password.
@@ -60,7 +62,10 @@ Edit `config.dev.toml` before the first run:
 ```toml
 default_theme = "system" # system | dark | light
 default_interface_skin = "rustbox" # rustbox | gmail | proton | zoho | outlook | fastmail | apple-mail | yahoo | hey | nord | github | gitlab | discord | slack | reddit | notion | ...
-log_level = "info" # trace | debug | info | warn | error | off; RUST_LOG overrides it
+log_level = "info" # RustBox app level; dependencies default to WARN. RUST_LOG can override the full filter.
+# Recommended dev filter: warn,rustbox=debug,tower_http=info
+# Avoid a global RUST_LOG=debug/info unless diagnosing a dependency: third-party
+# crates may emit internal filesystem/source paths in verbose records.
 # Mail hosts may be omitted: IMAP defaults to localhost:993 and SMTP to localhost:587.
 # imap_host = "localhost"
 # smtp_host = "localhost"
@@ -75,7 +80,7 @@ max_message_size_mb = 50
 sieve_enabled = true
 diagnostics_enabled = true
 about_enabled = true
-# Adds CSP/frame/referrer/permissions/COOP response headers when enabled.
+# Adds content-type-aware browser security headers when enabled: full document policy on HTML, private no-store/CORP/anti-framing policy on /api, Referrer-Policy on HTML/CSS, and nosniff broadly.
 security_headers_enabled = false
 
 # Optional; defaults to imap_host. Ignored when sieve_enabled=false.
@@ -125,10 +130,16 @@ bucket = "rustbox"
 region = "eu-central-1"
 # endpoint = "https://s3.example.com" # MinIO/Ceph RGW/etc.
 
+[sync]
+interval_secs = 30
+deep_index_batch_size = 10
+
 [search]
 backend = "opensearch"
 urls = ["https://opensearch.example.com:9200"]
 required = true
+# Production-safe default: do not proactively download every full message body.
+deep_index = false
 ```
 
 Shared POSIX is also supported without S3:
@@ -155,7 +166,7 @@ rustbox search reindex
 
 Ready Docker examples are in `docker/`: standalone SQLite, PostgreSQL + SILO (S3-compatible) + OpenSearch, and MySQL + NFS + OpenSearch.
 
-All executable application SQL is centralized by dialect under `src/queries/{sqlite,mysql,pgsql}/queries.rs`. The squashed compatibility baseline remains V046; RustBox 0.2.1 adds runtime migration V047 for attachment checksums/logical blob keys and the durable search outbox. The next migration number is V048. See `migrations/README.md`.
+All executable application SQL is centralized by dialect under `src/queries/{sqlite,mysql,pgsql}/queries.rs`. The squashed compatibility baseline remains V046; RustBox 0.2.1 adds runtime migration V047 for attachment checksums/logical blob keys and the durable search outbox, while RustBox 0.2.8 adds V048 for monotonic folder-counter generations used by race-safe IMAP counter reconciliation. The next migration number is V049. See `migrations/README.md`.
 
 
 ## Development
@@ -224,7 +235,7 @@ Initialize Git after extracting the release archive:
 ```bash
 git init
 git add .
-git commit -m "RustBox 0.2.6 release"
+git commit -m "RustBox 0.2.8 release"
 ./scripts/setup-upstream.sh
 ```
 

RELEASE-MANIFEST.txt

@@ -1,15 +1,20 @@
-RustBox 0.2.6 release manifest
+RustBox 0.2.8 release manifest
 
-0.2.6 feature/configuration changes:
+0.2.8 feature/configuration changes:
-- fixes iPhone/iOS Safari reader action menus by rendering open Details / Move / copy popovers outside the scrolling toolbar
+- fixes folder unread counts by treating IMAP STATUS UNSEEN as authoritative and never using SELECT/EXAMINE UNSEEN as a count
-- refreshes unread counters with server-reported unread counts and avoids frequent IMAP folder-list refreshes
+- falls back to UID SEARCH UNSEEN when STATUS is unavailable for the selected mailbox
-- watches the currently viewed folder with IMAP IDLE and synchronizes remaining folders on a 30-second fallback cadence
+- reconciles MESSAGES/UNSEEN even when HIGHESTMODSEQ is unchanged and rejects out-of-order stale counter writes with compare-and-set/retry
-- stores new message headers before realtime events, allowing newly arrived messages to appear live in the active list
+- updates individual message rows and folder counters optimistically/live for read/unread/flag events instead of rebuilding the message list, then reconciles them to authoritative IMAP state
-- shows an in-app toast for new mail in any folder and deduplicates browser notifications per message
+- shows wide folder badges as total / unread, hides the unread suffix at zero, and switches to compact counters in narrow sidebars
-- shows an animated indexing indicator beside Contacts while deep indexing is active
+- exposes IMAP header-cache and deep-index backlog through the activity indicator and tooltip
-- excludes Trash/Junk/Spam from the deep-index selection query
+- keeps counter STATUS separate from the CONDSTORE cursor, falls back to full UID/FLAGS reconciliation when needed, and refuses to apply partial IMAP streams
-- manual refresh forces current-folder message/count refresh while folder counters refresh in parallel
+- keeps security_headers_enabled opt-in, centralizes the RustBox-added browser security profile behind that switch, and applies the full document-only profile only to HTML/XHTML
-- no schema migration; V047 remains current and V048 remains next
+- uses external same-origin JavaScript with `script-src 'self'`, disables inline script attributes, restricts stylesheets to `style-src 'self'`, and permits only dynamic style attributes via `style-src-attr 'unsafe-inline'`
+- applies no-store, nosniff, same-origin CORP and an anti-framing `frame-ancestors 'none'`/X-Frame-Options policy to private API responses; the full document CSP plus Permissions-Policy/COOP remain HTML-only, and assets receive same-origin CORP where applicable
+- leaves HSTS to the HTTPS/TLS-terminating deployment layer
+- minimizes the public auth policy to rememberMeEnabled and moves optional feature availability behind authenticated /api/auth/session-policy
+- adds/extends regression coverage and offline release checks for the changed behavior
+- adds runtime migration V048 on SQLite/MySQL/PostgreSQL for monotonic folder-counter generations; V049 remains next
 
 Architecture:
 - database_backend = sqlite | mysql | pgsql selects authoritative SQL only
@@ -36,31 +41,8 @@ Database/schema:
 - migrations/{sqlite,mysql,pgsql}/schema.sql contain the current fresh schema
 - compatibility baseline remains V046
 - runtime migration V047 adds attachment checksum metadata and search_outbox
-- next migration number: V048
+- runtime migration V048 adds `folders.counter_generation` for race-safe authoritative IMAP counter writes
-
+- next migration number: V049
-PostgreSQL message mutation fix (0.2.2):
-- header_sync_generation UPSERT qualifies the current tenant user_meta.value on the UPDATE RHS
-- this prevents PostgreSQL from treating `value` as ambiguous during ON CONFLICT DO UPDATE
-- SQLite/MySQL equivalents were reviewed and require no matching SQL change
-- no schema migration is required
-
-PostgreSQL startup compile fix (0.2.2):
-- multi-statement global schema DDL uses `sqlx::Executor::execute()` on the transaction connection
-- avoids SQLx raw_sql mutable-connection lifetime inference failures (`Executor is not general enough`)
-- retains the startup transaction and `SET LOCAL client_min_messages TO WARNING`
-- no schema migration is required
-
-Database/session startup (0.2.2):
-- db::pool::configure() is the single owner of global schema initialization
-- database-backed session persistence does not execute schema.sql a second time
-- the fix applies uniformly to SQLite, MySQL and PostgreSQL
-- PostgreSQL expected IF NOT EXISTS notices are suppressed only inside the startup DDL transaction
-- no SQL migration is required; runtime schema remains V047
-
-SQLite test isolation (0.2.2):
-- test builds initialize each requested SQLite database but do not publish a TempDir-backed path into the process-wide database OnceLock
-- account/database tests therefore remain isolated when Rust runs them in parallel
-- a regression test covers deleting the first TempDir before opening a second test database
 
 Docker examples:
 - docker/compose-single-sqlite.yml
@@ -69,14 +51,14 @@ Docker examples:
 - docker/compose-mysql-nfs-opensearch.yml (MySQL + real NFS volume + OpenSearch)
 
 Operations/docs:
-- README.md documents 0.2.6 storage/search configuration
+- README.md documents 0.2.8 configuration
 - docker/README.md documents Compose variants
 - docs/STORAGE_SEARCH_OPERATIONS.md documents failure modes, shared-storage requirements and migration behavior
 - TODO.md leaves live SILO/MinIO/AWS/Ceph and real multi-node acceptance validation explicitly pending
 
 Build/release metadata:
 - `scripts/package-release.sh` runs the full Rust release gate before creating ZIP/SHA256 artifacts
-- Cargo.toml version = 0.2.6
+- Cargo.toml version = 0.2.8
 - rust-toolchain.toml pins Rust 1.99.1
 - Cargo.lock is retained for reproducible application builds; the release gate generates it only when missing
 - CI and scripts/build-release.sh use the retained Cargo.lock (generating it only if missing), then run locked tests/Clippy/release build

RELEASE-VALIDATION.txt

@@ -1,46 +1,29 @@
-RustBox 0.2.6 - final source validation
+RustBox 0.2.8 - final source validation
 
-0.2.6 scope:
+0.2.8 scope:
-- iOS-safe reader action popovers for Details and Move / copy, portaled outside the horizontally scrolling toolbar
+- authoritative IMAP folder totals/unread counters from server state, including selected-mailbox fallback via UID SEARCH UNSEEN
-- faster folder-counter refresh using a server-authoritative realtime unread counts and a longer folder-list cache TTL
+- optimistic/targeted realtime read/unread/flag updates without full message-list rerenders
-- live refresh for the currently viewed folder via IMAP IDLE plus a 30-second fallback sync for other folders
+- responsive total/unread folder badges, authoritative FolderStatus updates, and separate counter/CONDSTORE cursor handling
-- periodic sync stores newly arrived message headers before emitting realtime events, so new messages can appear in the list immediately
+- IMAP cache/deep-index progress surfaced through the activity indicator
-- in-app toast for new mail in any folder and per-message browser-notification deduplication
+- content-type-aware opt-in security headers with external-script `script-src 'self'` CSP and stylesheet-only `style-src 'self'`
-- animated indexing indicator beside Contacts while deep indexing is active
+- private API no-store/nosniff/same-origin-CORP plus anti-framing CSP/X-Frame-Options; full document CSP, Permissions-Policy and COOP remain HTML-only
-- deep indexing excludes Trash/Junk/Spam at query time so excluded folders cannot block the indexing queue
+- pre-login auth policy minimized to rememberMeEnabled; optional feature policy requires authentication
-- manual refresh forces current-folder status refresh while folder-list/count refresh runs in parallel
+- runtime migration V048 adds monotonic folder-counter generations on SQLite/MySQL/PostgreSQL; V049 remains next
-- no database migration; V047 remains current and V048 remains next
+- version metadata updated to 0.2.8
-- version metadata updated to 0.2.6
 
 Completed in this environment:
-- offline release validator: scripts/validate-release-static.py (212/212 checks passed)
+- offline release validator: scripts/validate-release-static.py (279/279 checks passed)
-- all maintained TOML examples parse successfully
+- browser JavaScript assembled in manifest order passes `node --check`
-- Docker Compose topology/config references are validated by the offline release validator
+- all JSON files parse successfully
-- JSON files parse successfully
-- browser JavaScript assembled in src/web/js/manifest.txt order passes node --check
-- shell scripts pass bash -n
 - Python helper scripts compile successfully
-- targeted source checks validate the PostgreSQL header-sync UPSERT and startup schema-initialization control flow
+- shell scripts pass `bash -n`
-- the PostgreSQL startup DDL path now uses `Executor::execute()` instead of the lifetime-problematic `raw_sql(...).execute(&mut PgConnection)` path; compiler validation remains part of the Rust-host release gate
+- release metadata consistently identifies 0.2.8
-- whitespace/patch-artifact checks pass on the final source tree (this packaged worktree has no `.git` metadata)
+- V048 migration files/catalog registration and SQLite upgrade execution are validated offline
-- Cargo.lock is retained for reproducible builds; no *.orig, *.rej, temporary FIX/APPLY scripts, or patch leftovers are shipped
-- regression source checks retain the PostgreSQL header-sync qualification audit and now reject the SQLx raw_sql mutable-connection lifetime regression in startup DDL
-- SQLite unit-test configuration no longer leaks a temporary database path through the process-wide OnceLock; a dedicated regression test covers deleted TempDir reuse
-- the static release contract now verifies that build-release.sh requires cargo test, Clippy with -D warnings, and a locked release build
-- scripts/package-release.sh runs the full build gate before creating the source ZIP and SHA256, so packaging cannot succeed after a failed Rust test/Clippy/build gate
 
-0.2.2 fixes included:
-- PostgreSQL startup schema initialization no longer triggers SQLx `Executor is not general enough`; raw multi-statement DDL is executed directly through `Executor::execute()` inside the existing transaction
-- PostgreSQL header-sync invalidation qualifies the existing tenant user_meta.value in ON CONFLICT DO UPDATE, eliminating the ambiguous-column 500 seen during message mutations such as marking spam
-- tenant SQL rewriting has a regression test proving the qualified user_meta reference is rewritten to the tenant table
-- SQLite and MySQL equivalents were reviewed and do not have the PostgreSQL ambiguity
-- 0.2.2 single-schema-owner and PostgreSQL NOTICE-noise fixes remain in place
-- no database migration is required; V047 remains current and V048 remains next
-- 0.2.1 OpenPGP visibility, OpenSearch backpressure and HTTP/dev cookie fixes remain in place
 
-Not executed in this packaging environment:
+Not executable in this packaging environment:
-- cargo fmt/test/clippy/build with Rust 1.99.1, because Rust/Cargo is not installed in this validation environment
+- cargo fmt/test/clippy/build with Rust 1.99.1, because Rust/Cargo is not installed
-- live PostgreSQL/MySQL/S3/NFS/OpenSearch integration tests
+- live PostgreSQL/MySQL/S3/NFS/OpenSearch/IMAP integration tests
 
 The final release gate on a Rust host is:
   bash scripts/build-release.sh

build.rs

@@ -58,9 +58,11 @@ fn main() {
     let out = PathBuf::from(env::var_os("OUT_DIR").expect("OUT_DIR"));
     let css_dir = root.join("src/web/css");
     let js_dir = root.join("src/web/js");
+    let theme_bootstrap_path = root.join("src/web/theme-bootstrap.js");
 
     for path in [
         root.join("src/web/index.html"),
+        theme_bootstrap_path.clone(),
         root.join("src/web/icons.svg"),
         root.join("src/web/i18n/en.json"),
         root.join("src/web/i18n/pl.json"),
@@ -70,8 +72,14 @@ fn main() {
 
     let css_bundle = bundle_manifest(&root, &css_dir, &css_dir.join("manifest.txt"), ".css");
     let js_bundle = bundle_manifest(&root, &js_dir, &js_dir.join("manifest.txt"), ".js");
+    let theme_bootstrap = fs::read_to_string(&theme_bootstrap_path)
+        .unwrap_or_else(|error| panic!("{}: {error}", theme_bootstrap_path.display()));
 
-    let asset_id = fnv1a64(&[css_bundle.as_bytes(), js_bundle.as_bytes()]);
+    let asset_id = fnv1a64(&[
+        css_bundle.as_bytes(),
+        js_bundle.as_bytes(),
+        theme_bootstrap.as_bytes(),
+    ]);
     println!("cargo:rustc-env=RUSTBOX_ASSET_ID={asset_id:016x}");
 
     fs::write(out.join("rustbox-ui.css"), css_bundle).expect("write RustBox CSS bundle");

config.dev.toml

@@ -52,3 +52,51 @@ sieve_allow_insecure_auth = false
 sieve_timeout_secs = 10
 
 trusted_proxies = "127.0.0.1,::1"
+[sync]
+interval_secs = 30
+# Maximum number of full message bodies fetched from IMAP during one sync pass when
+# automatic deep indexing is enabled. Higher values fill the cache/index faster but
+# increase network traffic, application database/search-storage usage and indexing CPU/I/O bursts.
+deep_index_batch_size = 10
+
+# Development search/cache profile.
+[search]
+backend = "local_tantivy"
+# Force automatic full-body cache/index for every account in this development instance.
+# Each periodic sync may download up to sync.deep_index_batch_size full MIME bodies.
+# This is intentionally ON in dev so cache/index behaviour is visible during testing.
+# Setting it to false falls back to the existing per-account deep_index preference.
+deep_index = true
+# Search outbox worker cadence/batch; these do NOT control IMAP body downloads.
+worker_interval_secs = 2
+worker_batch_size = 100
+worker_max_attempts = 12
+
+
+# Periodic IMAP reconciliation. Active folders still use IMAP IDLE for near-real-time
+# updates; this interval controls the fallback/background pass for counters, flags,
+# new headers in other folders, and the automatic deep-index pass. Lower values make
+# background state converge faster but increase IMAP traffic and server load.
+
+# Administrator-only system diagnostics endpoint. Disabled by default.
+# When enabled it exposes a redacted runtime/configuration report plus live probes
+# for SQL, session persistence (database/Redis), blob storage (filesystem/S3),
+# search (Tantivy/OpenSearch), IMAP IDLE counters and security telemetry.
+# Access requires BOTH an allowed source network and the configured auth method.
+# Secrets (passwords, tokens, S3 keys, session keys and URL credentials) are never returned.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+# Default/fail-safe allowlist: only this host. Add trusted LAN/pod/monitoring CIDRs explicitly.
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+# token | basic. Credentials should normally come from .env / secret manager, not TOML.
+auth = "token"
+# token = "replace-with-at-least-24-random-characters"
+# basic_username = "rustbox-monitor"
+# basic_password = "replace-with-a-long-random-password"
+# E-mail addresses and stable user hashes are omitted by default; aggregate counts remain available.
+include_user_identifiers = false
+# Timeout applied independently to database/session/storage/search probes.
+probe_timeout_secs = 5
+# Rolling in-memory window used for login failures, 403, 429 and 5xx attack/problem signals.
+security_window_secs = 900

config.example.toml

@@ -1,4 +1,4 @@
-# RustBox 0.2.6
+# RustBox 0.2.8
 host = "127.0.0.1"
 port = 3001
 environment = "production"
@@ -59,7 +59,7 @@ max_message_size_mb = 50
 sieve_enabled = true
 diagnostics_enabled = true
 about_enabled = true
-# Adds browser-facing security headers (CSP, frame/referrer/permissions policies).
+# Adds content-type-aware browser security headers: document policies on HTML, private no-store/framing/CORP policy on /api, Referrer-Policy on HTML/CSS, and nosniff broadly.
 security_headers_enabled = false
 
 # ManageSieve. If sieve_host is omitted, imap_host from the authenticated
@@ -72,7 +72,6 @@ sieve_allow_insecure_auth = false
 sieve_timeout_secs = 10
 
 trusted_proxies = "127.0.0.1,::1"
-
 # Optional server-wide defaults for special IMAP folders. These are used when
 # a mailbox has no per-account override and the named folder exists.
 # default_sent_folder = "Sent"
@@ -96,10 +95,6 @@ pgp_max_key_bytes = 1048576
 # Private-key export is deliberately disabled unless the administrator opts in.
 pgp_allow_private_export = false
 
-# RustBox 0.2 blob/search backends
-# Blob storage is independent from the SQL database. PostgreSQL/MySQL can still use
-# local filesystem storage in single-node mode. In cluster mode use S3-compatible
-# storage or a genuinely shared POSIX filesystem (NFS/CephFS/GlusterFS).
 [storage]
 backend = "filesystem" # filesystem | s3
 # path = "/var/lib/rustbox/blobs" # defaults to data_dir for filesystem
@@ -120,6 +115,17 @@ retry_timeout_secs = 60
 # server_side_encryption = "AES256" # or "aws:kms"
 # kms_key_id = "..."
 
+# Periodic IMAP reconciliation. Active folders still use IMAP IDLE; this is the
+# background/fallback cadence for folder counters, flags, new headers in other
+# folders, and the automatic deep-index pass. Lower values improve convergence but
+# increase IMAP traffic and mail-server load.
+[sync]
+interval_secs = 30
+# Maximum full message bodies downloaded from IMAP per periodic pass when deep index
+# is effective. Larger batches catch up faster at the cost of network traffic,
+# application-database/search-storage usage and indexing CPU/I/O.
+deep_index_batch_size = 10
+
 # Search is independent from blob storage. Local Tantivy is single-node only.
 [search]
 backend = "local_tantivy" # disabled | local_tantivy | opensearch
@@ -129,8 +135,45 @@ index_prefix = "rustbox"
 required = false
 allow_insecure_http = false
 request_timeout_secs = 10
+# Server-wide automatic full-body cache/index switch. When true, RustBox proactively
+# downloads message bodies from IMAP and indexes them for every account, up to
+# sync.deep_index_batch_size per sync pass. This increases IMAP traffic,
+# application-database/search-storage usage and indexing load. Production default
+# is false. When false,
+# the existing per-account deep_index preference may still opt an account in.
+deep_index = false
+# Search outbox worker cadence/batch; these do NOT control IMAP body downloads.
 worker_interval_secs = 2
 worker_batch_size = 100
 worker_max_attempts = 8
 # username = "rustbox"
 # password = "..."
+
+
+# RustBox 0.2 blob/search backends
+# Blob storage is independent from the SQL database. PostgreSQL/MySQL can still use
+# local filesystem storage in single-node mode. In cluster mode use S3-compatible
+# storage or a genuinely shared POSIX filesystem (NFS/CephFS/GlusterFS).
+
+# Administrator-only system diagnostics endpoint. Disabled by default.
+# When enabled it exposes a redacted runtime/configuration report plus live probes
+# for SQL, session persistence (database/Redis), blob storage (filesystem/S3),
+# search (Tantivy/OpenSearch), IMAP IDLE counters and security telemetry.
+# Access requires BOTH an allowed source network and the configured auth method.
+# Secrets (passwords, tokens, S3 keys, session keys and URL credentials) are never returned.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+# Default/fail-safe allowlist: only this host. Add trusted LAN/pod/monitoring CIDRs explicitly.
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+# token | basic. Credentials should normally come from .env / secret manager, not TOML.
+auth = "token"
+# token = "replace-with-at-least-24-random-characters"
+# basic_username = "rustbox-monitor"
+# basic_password = "replace-with-a-long-random-password"
+# E-mail addresses and stable user hashes are omitted by default; aggregate counts remain available.
+include_user_identifiers = false
+# Timeout applied independently to database/session/storage/search probes.
+probe_timeout_secs = 5
+# Rolling in-memory window used for login failures, 403, 429 and 5xx attack/problem signals.
+security_window_secs = 900

dev.sh

@@ -4,6 +4,17 @@ set -euo pipefail
 ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 cd "$ROOT"
 
+# Local development settings live in .env. RustBox reads environment variables
+# from the process; it does not parse dotenv files itself. Export the file here
+# before applying development defaults so explicit .env values always win.
+ENV_FILE="${RUSTBOX_ENV_FILE:-$ROOT/.env}"
+if [ -f "$ENV_FILE" ]; then
+  set -a
+  # shellcheck disable=SC1090
+  . "$ENV_FILE"
+  set +a
+fi
+
 if ! command -v cargo >/dev/null 2>&1; then
   echo "error: Rust/Cargo is required" >&2
   exit 1
@@ -12,7 +23,28 @@ fi
 mkdir -p "$ROOT/.dev/data"
 export RUSTBOX_CONFIG="${RUSTBOX_CONFIG:-$ROOT/config.dev.toml}"
 export DATA_DIR="${DATA_DIR:-$ROOT/.dev/data}"
-export RUST_LOG="${RUST_LOG:-rustbox=debug,tower_http=info}"
+
+# Keep application debugging useful without enabling verbose INFO/DEBUG output
+# from every dependency. A legacy/simple RUST_LOG level from .env is scoped to
+# RustBox automatically; explicit directive filters (containing '=' or ',') are
+# respected exactly as provided.
+case "${RUST_LOG:-}" in
+  ""|debug)
+    export RUST_LOG="warn,rustbox=debug,tower_http=info"
+    ;;
+  trace)
+    export RUST_LOG="warn,rustbox=trace,tower_http=debug"
+    ;;
+  info)
+    export RUST_LOG="warn,rustbox=info,tower_http=info"
+    ;;
+  warn|error|off)
+    export RUST_LOG="${RUST_LOG}"
+    ;;
+  *)
+    export RUST_LOG="${RUST_LOG}"
+    ;;
+esac
 
 if [ ! -f "$RUSTBOX_CONFIG" ]; then
   echo "error: config not found: $RUSTBOX_CONFIG" >&2
@@ -20,8 +52,22 @@ if [ ! -f "$RUSTBOX_CONFIG" ]; then
 fi
 
 echo "RustBox: http://127.0.0.1:3001"
-echo "Config: $RUSTBOX_CONFIG"
+display_path() {
-echo "Data:   $DATA_DIR"
+  local value="$1"
+  if [[ "$value" == "$ROOT"/* ]]; then
+    printf './%s' "${value#"$ROOT"/}"
+  else
+    printf '%s' "$(basename "$value")"
+  fi
+}
+
+echo "Config: $(display_path "$RUSTBOX_CONFIG")"
+echo "Data:   $(display_path "$DATA_DIR")"
+if [ -f "$ENV_FILE" ]; then
+  echo "Env:    $(display_path "$ENV_FILE")"
+fi
+echo "IMAP:   ${IMAP_HOST:-localhost}:${IMAP_PORT:-993}"
+echo "SMTP:   ${SMTP_HOST:-${IMAP_HOST:-localhost}}:${SMTP_PORT:-587}"
 echo
 
 cargo run --quiet --bin rustbox -- --check-config

docker/.env.example

@@ -15,7 +15,7 @@ SMTP_PORT=587
 TLS_ENABLED=true
 
 # Application logging.
-RUST_LOG=info
+RUST_LOG=warn,rustbox=info,tower_http=info
 
 # Shared session encryption key. Required to be identical on all RustBox nodes.
 # Replace for any non-local deployment.
@@ -52,3 +52,12 @@ COMPOSE_PROJECT_NAME=rustbox
 
 # development = cookies work over plain HTTP; production = Secure cookies, requires HTTPS
 ENVIRONMENT=development
+
+# Administrator-only diagnostics endpoint (requires corresponding TOML section).
+# DIAGNOSTICS_ENDPOINT__ENABLED=true
+# DIAGNOSTICS_ENDPOINT__AUTH=token
+# DIAGNOSTICS_ENDPOINT__TOKEN=replace-with-at-least-24-random-characters
+# Alternative Basic Auth:
+# DIAGNOSTICS_ENDPOINT__AUTH=basic
+# DIAGNOSTICS_ENDPOINT__BASIC_USERNAME=rustbox-monitor
+# DIAGNOSTICS_ENDPOINT__BASIC_PASSWORD=replace-with-a-long-random-password

docker/README.md

@@ -80,7 +80,7 @@ cp .env.example .env
 | `SMTP_HOST` | `mail.example.com` | all | SMTP server hostname used for sending mail. |
 | `SMTP_PORT` | `587` | all | SMTP submission port. |
 | `TLS_ENABLED` | `true` | all | Enables TLS for mail connections according to RustBox configuration. |
-| `RUST_LOG` | `info` | all | Rust logging filter/level. |
+| `RUST_LOG` | `warn,rustbox=info,tower_http=info` | all | Rust logging filter. Keeps dependencies quiet by default; use explicit target directives for dependency debugging. |
 | `SESSION_ENCRYPTION_KEY` | development key | PostgreSQL, MySQL | Shared key used to encrypt session data. All application nodes must use the same value. Replace it outside local testing. |
 | `POSTGRES_PASSWORD` | `rustbox-dev-password` | PostgreSQL | Password for PostgreSQL user `rustbox`; also used in `DATABASE_URL`. |
 | `S3_ACCESS_KEY` | `rustbox` | PostgreSQL/S3 | Access key for the bundled S3-compatible SILO service and RustBox S3 client. |
@@ -201,4 +201,4 @@ docker compose -p rustbox -f compose-postgres-s3-opensearch.yml exec opensearch
   -d '{"index.blocks.read_only_allow_delete":null}'
 ```
 
-RustBox 0.2.6 retains the OpenSearch outbox backoff introduced in 0.2.2, so these 429/flood-stage responses no longer produce one warning per queued event on a full disk.
+RustBox 0.2.8 retains the OpenSearch outbox backoff introduced in 0.2.2, so these 429/flood-stage responses no longer produce one warning per queued event on a full disk.

docker/compose-ha-garage.yml

@@ -23,7 +23,7 @@ x-rustbox-common: &rustbox-common
     SMTP_HOST: ${SMTP_HOST:-mail.example.com}
     SMTP_PORT: ${SMTP_PORT:-587}
     TLS_ENABLED: ${TLS_ENABLED:-true}
-    RUST_LOG: ${RUST_LOG:-info}
+    RUST_LOG: ${RUST_LOG:-warn,rustbox=info,tower_http=info}
     DATABASE_URL: postgres://rustbox:${POSTGRES_PASSWORD:-rustbox-dev-password}@postgres:5432/rustbox
     SESSION_ENCRYPTION_KEY: ${SESSION_ENCRYPTION_KEY:-MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=}
     AWS_ACCESS_KEY_ID: ${GARAGE_ACCESS_KEY_ID:-GKb69252a3b0643e8bd08d4cd4}

docker/compose-mysql-nfs-opensearch.yml

@@ -52,7 +52,7 @@ services:
       SMTP_HOST: ${SMTP_HOST:-mail.example.com}
       SMTP_PORT: ${SMTP_PORT:-587}
       TLS_ENABLED: ${TLS_ENABLED:-true}
-      RUST_LOG: ${RUST_LOG:-info}
+      RUST_LOG: ${RUST_LOG:-warn,rustbox=info,tower_http=info}
       DATABASE_URL: mysql://rustbox:${MYSQL_PASSWORD:-rustbox-dev-password}@mysql:3306/rustbox
       SESSION_ENCRYPTION_KEY: ${SESSION_ENCRYPTION_KEY:-MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=}
     volumes:

docker/compose-postgres-s3-opensearch.yml

@@ -76,7 +76,7 @@ services:
       SMTP_HOST: ${SMTP_HOST:-mail.example.com}
       SMTP_PORT: ${SMTP_PORT:-587}
       TLS_ENABLED: ${TLS_ENABLED:-true}
-      RUST_LOG: ${RUST_LOG:-info}
+      RUST_LOG: ${RUST_LOG:-warn,rustbox=info,tower_http=info}
       DATABASE_URL: postgres://rustbox:${POSTGRES_PASSWORD:-rustbox-dev-password}@postgres:5432/rustbox
       SESSION_ENCRYPTION_KEY: ${SESSION_ENCRYPTION_KEY:-MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=}
       AWS_ACCESS_KEY_ID: ${S3_ACCESS_KEY:-rustbox}

docker/compose-single-sqlite.yml

@@ -17,7 +17,7 @@ services:
       SMTP_HOST: ${SMTP_HOST:-mail.example.com}
       SMTP_PORT: ${SMTP_PORT:-587}
       TLS_ENABLED: ${TLS_ENABLED:-true}
-      RUST_LOG: ${RUST_LOG:-info}
+      RUST_LOG: ${RUST_LOG:-warn,rustbox=info,tower_http=info}
     volumes:
       - ./configs/single-sqlite.toml:/etc/rustbox/rustbox.toml:ro
       - rustbox-data:/var/lib/rustbox

docker/configs/ha-garage.toml

@@ -21,8 +21,16 @@ path_style = true
 allow_http = true
 prefix = "mail"
 
+[sync]
+# Background IMAP reconciliation cadence; active folders still use IDLE.
+interval_secs = 30
+# Full bodies fetched per pass when search.deep_index is effective.
+deep_index_batch_size = 10
+
 [search]
 backend = "opensearch"
+# Dev: proactively cache/index full message bodies for testing.
+deep_index = true
 urls = ["http://opensearch:9200"]
 index_prefix = "rustbox"
 allow_insecure_http = true
@@ -30,3 +38,16 @@ required = true
 worker_interval_secs = 2
 worker_batch_size = 100
 worker_max_attempts = 8
+
+# Administrator-only system diagnostics. Disabled by default and loopback-only when enabled.
+# For monitoring in Docker/Kubernetes, explicitly add the monitoring/pod CIDR and keep
+# token/basic credentials in the orchestrator secret store.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "token"
+include_user_identifiers = false
+probe_timeout_secs = 5
+security_window_secs = 900
+

docker/configs/mysql-nfs-opensearch.toml

@@ -11,8 +11,16 @@ backend = "filesystem"
 path = "/mnt/rustbox-shared"
 shared = true
 
+[sync]
+# Background IMAP reconciliation cadence; active folders still use IDLE.
+interval_secs = 30
+# Full bodies fetched per pass when search.deep_index is effective.
+deep_index_batch_size = 10
+
 [search]
 backend = "opensearch"
+# Production: do not proactively download/store every full message body.
+deep_index = false
 urls = ["http://opensearch:9200"]
 index_prefix = "rustbox"
 allow_insecure_http = true
@@ -20,3 +28,16 @@ required = true
 worker_interval_secs = 2
 worker_batch_size = 100
 worker_max_attempts = 8
+
+# Administrator-only system diagnostics. Disabled by default and loopback-only when enabled.
+# For monitoring in Docker/Kubernetes, explicitly add the monitoring/pod CIDR and keep
+# token/basic credentials in the orchestrator secret store.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "token"
+include_user_identifiers = false
+probe_timeout_secs = 5
+security_window_secs = 900
+

docker/configs/postgres-s3-opensearch.toml

@@ -15,8 +15,16 @@ path_style = true
 allow_http = true
 prefix = "mail"
 
+[sync]
+# Background IMAP reconciliation cadence; active folders still use IDLE.
+interval_secs = 30
+# Full bodies fetched per pass when search.deep_index is effective.
+deep_index_batch_size = 10
+
 [search]
 backend = "opensearch"
+# Production: do not proactively download/store every full message body.
+deep_index = false
 urls = ["http://opensearch:9200"]
 index_prefix = "rustbox"
 allow_insecure_http = true
@@ -24,3 +32,16 @@ required = true
 worker_interval_secs = 2
 worker_batch_size = 100
 worker_max_attempts = 8
+
+# Administrator-only system diagnostics. Disabled by default and loopback-only when enabled.
+# For monitoring in Docker/Kubernetes, explicitly add the monitoring/pod CIDR and keep
+# token/basic credentials in the orchestrator secret store.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "token"
+include_user_identifiers = false
+probe_timeout_secs = 5
+security_window_secs = 900
+

docker/configs/single-sqlite.toml

@@ -12,6 +12,27 @@ backend = "filesystem"
 path = "/var/lib/rustbox/blobs"
 shared = false
 
+[sync]
+# Background IMAP reconciliation cadence; active folders still use IDLE.
+interval_secs = 30
+# Full bodies fetched per pass when search.deep_index is effective.
+deep_index_batch_size = 10
+
 [search]
 backend = "local_tantivy"
+# Production: do not proactively download/store every full message body.
+deep_index = false
 path = "/var/lib/rustbox/search"
+
+# Administrator-only system diagnostics. Disabled by default and loopback-only when enabled.
+# For monitoring in Docker/Kubernetes, explicitly add the monitoring/pod CIDR and keep
+# token/basic credentials in the orchestrator secret store.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "token"
+include_user_identifiers = false
+probe_timeout_secs = 5
+security_window_secs = 900
+

docs/IMPLEMENTATION_STATUS.md

@@ -1,8 +1,18 @@
-# RustBox 0.2.6 - implementation status
+# RustBox 0.2.8 - implementation status
 
-This file tracks the `0.2.6` source snapshot. Storage/search scope and outstanding acceptance work are tracked in `TODO.md`. A feature is only listed as implemented when working code exists in this source tree; partial items are called out explicitly.
+This file tracks the `0.2.8` source snapshot. Storage/search scope and outstanding acceptance work are tracked in `TODO.md`. A feature is only listed as implemented when working code exists in this source tree; partial items are called out explicitly.
 
-## 0.2.6 storage/search architecture
+## 0.2.8 browser security headers
+
+- `security_headers_enabled` remains opt-in and disabled by default for compatibility; optional browser-security headers are centralized in this middleware, so disabling it removes the RustBox-added security profile while normal response semantics such as `Content-Type` and route-specific caching remain.
+- HTML/XHTML documents receive the full document profile: CSP, `X-Frame-Options: DENY`, `Permissions-Policy`, `Cross-Origin-Opener-Policy: same-origin`, `Referrer-Policy: no-referrer` and `X-Content-Type-Options: nosniff`.
+- The HTML CSP allows only same-origin scripts (`script-src 'self'`) and disables inline script attributes; the theme bootstrap is an external fingerprinted asset. Stylesheets are same-origin only (`style-src 'self'`), while `style-src-attr 'unsafe-inline'` is narrowly retained because the current UI still sets per-element style attributes dynamically.
+- Private `/api` responses receive `Cache-Control: no-store`, `X-Content-Type-Options: nosniff`, `Cross-Origin-Resource-Policy: same-origin`, `Content-Security-Policy: frame-ancestors 'none'` and legacy-compatible `X-Frame-Options: DENY`. API JSON does not receive the full document CSP, `Permissions-Policy`, COOP or `Referrer-Policy`.
+- CSS receives `Referrer-Policy: no-referrer` and `X-Content-Type-Options: nosniff`; application assets also receive same-origin CORP without redundant HTML document policies.
+- HSTS is deliberately not synthesized by RustBox because the application may sit behind a TLS-terminating reverse proxy and cannot reliably determine the public HTTPS boundary; HSTS belongs at that HTTPS edge.
+- The public `/api/auth/policy` is data-minimized to the single login-form capability `rememberMeEnabled`. Optional feature availability (OpenPGP, Sieve, diagnostics, About) is returned only from authenticated `/api/auth/session-policy`; session/remember durations are not exposed to the browser policy endpoints.
+
+## 0.2.8 storage/search architecture
 
 - SQL backend selection (`sqlite`/`mysql`/`pgsql`) is independent from blob storage and search backend selection.
 - Cluster mode clears an implicit/default `data_dir`; PostgreSQL/MySQL single-node deployments may still intentionally use `data_dir`-backed filesystem storage and local Tantivy.
@@ -10,7 +20,7 @@ This file tracks the `0.2.6` source snapshot. Storage/search scope and outstandi
 - Draft attachment upload/read/delete/snapshot/send paths use the `BlobStorage` abstraction and logical object keys instead of assuming node-local paths.
 - OpenSearch is available as the cluster-capable indexer. Local Tantivy remains single-node only; search may also be disabled.
 - Search mutations use a durable SQL outbox with claim/lease, retry/backoff and dead-letter state; the index remains rebuildable derived state.
-- V047 adds attachment checksum metadata and the search outbox across SQLite, MySQL and PostgreSQL.
+- V047 adds attachment checksum metadata and the search outbox across SQLite, MySQL and PostgreSQL. V048 adds monotonic folder-counter generations used by compare-and-set reconciliation of authoritative IMAP counts; V049 is reserved as the next migration number.
 - SQL global-schema initialization is centralized in `db::pool::configure()`; database-backed sessions do not repeat startup DDL for SQLite, MySQL or PostgreSQL.
 - Docker Compose examples cover standalone SQLite, PostgreSQL + SILO (S3-compatible) + OpenSearch, and MySQL + NFS + OpenSearch.
 - Live SILO/MinIO/AWS S3/Ceph RGW, live NFS multi-host, live OpenSearch and full multi-node failover acceptance remain release-environment validation items and are not represented as completed here.
@@ -26,6 +36,11 @@ This file tracks the `0.2.6` source snapshot. Storage/search scope and outstandi
 
 ### Mail and IMAP workflow
 
+- Folder totals and unread counters use authoritative IMAP `STATUS (... MESSAGES UNSEEN ...)` data. If STATUS is unavailable for a selected mailbox, RustBox falls back to `UID SEARCH UNSEEN`; it never treats SELECT/EXAMINE `UNSEEN` (the first unseen sequence number) as an unread count.
+- Folder counter reconciliation runs independently from content synchronization and repairs `MESSAGES/UNSEEN` even when `HIGHESTMODSEQ` is unchanged. A manual counter refresh reuses the cached folder tree while it is fresh and batches STATUS calls on one IMAP session instead of forcing another LIST.
+- Read/unread/flag mutations update the affected row/badge optimistically, then reconcile against authoritative IMAP state and publish targeted flag/`FolderStatus` events without replacing the whole message list. The active folder is watched through IMAP IDLE; other folders are reconciled every 30 seconds.
+- Large folders may hydrate message headers incrementally, but the sidebar total/unread badge remains server-authoritative. IDLE/periodic reconciliation keeps the CONDSTORE cursor separate from counter refresh, falls back to a full `UID FLAGS` comparison when CONDSTORE is unavailable, and discards partial IMAP fetch streams rather than applying incomplete state. The top-right activity indicator distinguishes active synchronization/indexing from an incomplete local IMAP header cache and exposes backlog details in its tooltip.
+- Wide folder badges display `total / unread` while unread is non-zero and total alone at zero; narrow sidebars switch to the compact existing counter presentation.
 - IMAP folder list, hierarchy, create, create subfolder, rename, delete, subscribe/unsubscribe, plus collapsible branch navigation with per-account remembered expansion state.
 - Special folders stored per account: Sent, Drafts, Trash, Junk and Archive. Spam/Junk additionally supports a browser-wide default destination with a per-account override and IMAP special-use/name fallback.
 - Special-folder references follow folder renames and are cleared when a referenced folder is deleted.
@@ -98,6 +113,7 @@ This file tracks the `0.2.6` source snapshot. Storage/search scope and outstandi
 - Account switch/remove/add workflow for multiple authenticated accounts in one browser session.
 - Active-session list across browsers while the RustBox process is running, with creation/last-active timestamps, friendly browser/device labels, full User-Agent hover detail, individual revoke and revoke-all-others.
 - Diagnostics panel exposing IMAP capabilities (including persistent custom-keyword support), authenticated SMTP connectivity, ManageSieve status, browser WebSocket state, local synchronization-cache timestamps/counts and live IMAP IDLE task/subscriber counts without returning server host names or credentials. Public liveness (`/api/health`) and local-storage readiness (`/api/ready`) endpoints are available for service supervision.
+- Optional administrator system diagnostics endpoint (disabled by default) supports explicit IP/CIDR allowlisting plus token/Basic authentication, redacts configured secrets, probes SQL/session/storage/search backends, reports active sessions and IMAP IDLE state, and surfaces bounded node-local security signals for failed logins, 403/429 responses and 5xx failures.
 - Search-index diagnostics expose cached/indexed counts, with a rebuild operation from the configured account-data backend.
 - IMAP reconnect control drops reusable request-path sessions and verifies a fresh authenticated connection.
 - Graceful SIGTERM/Ctrl+C shutdown stops accepting new requests and aborts dedicated IMAP IDLE tasks before process exit.

docs/RELEASING.md

@@ -26,7 +26,7 @@ RUSTBOX_CONFIG=./config.dev.toml ./target/release/rustbox --check-config
 
 Browser JavaScript source lives in functional modules under `src/web/js/`, ordered by `src/web/js/manifest.txt`. `build.rs` concatenates those modules into the embedded `rustbox-ui.js` asset during every Cargo build. The repository has no duplicate `ui/` snapshot; `src/web/` is the only browser UI source.
 
-## Updating an existing checkout to 0.2.6
+## Updating an existing checkout to 0.2.8
 
 Do not overlay the release with `cp *` or another command that skips dotfiles. That can retain stale `.github`, `.env.example`, or `Cargo.lock` files.
 

docs/STORAGE_SEARCH_OPERATIONS.md

@@ -1,6 +1,6 @@
-# RustBox 0.2.6 storage/search operations
+# RustBox 0.2.8 storage/search operations
 
-RustBox 0.2.6 treats SQL, blob storage and search as independent capabilities. The database engine does not decide whether `data_dir` is allowed.
+RustBox 0.2.8 treats SQL, blob storage and search as independent capabilities. The database engine does not decide whether `data_dir` is allowed.
 
 ## Deployment matrix
 
@@ -50,6 +50,14 @@ The rebuild removes superseded outbox events older than the rebuild start and ke
 
 If `search.required=false`, an unavailable OpenSearch backend may leave the application usable while the outbox grows; readiness reports degraded search and workers retry later. With `search.required=true`, search health is a startup/readiness requirement.
 
+### Automatic body cache / deep index
+
+Automatic full-body caching is controlled by `search.deep_index`. When it is `true` and the search backend is enabled, every periodic IMAP reconciliation may fetch full MIME bodies for messages that have headers cached but no body/index yet. `sync.deep_index_batch_size` caps the number of bodies fetched in one pass. Full bodies are stored in the per-account application database/cache and then queued/indexed, so enabling this increases IMAP bandwidth, application-database/search-storage use and indexing CPU/I/O.
+
+`search.deep_index=false` is the production default. It prevents a server-wide forced full-mailbox download, but preserves the existing per-account `deep_index` opt-in. Development configuration sets `search.deep_index=true` so cache/index behavior is exercised without an additional preference change.
+
+`sync.interval_secs` controls the periodic reconciliation cadence. Active folders still use IMAP IDLE for near-real-time events; the periodic pass is the fallback/background reconciliation for counters, flags and headers in other folders and is also the cadence for automatic deep-index batches. Lower values converge faster but create more IMAP requests.
+
 ## Failure behavior
 
 - SQL unavailable: authoritative mailbox/session/account operations cannot proceed.

docs/SYSTEM_DIAGNOSTICS.md

@@ -0,0 +1,149 @@
+# Administrator system diagnostics endpoint
+
+RustBox can expose a single administrator-only JSON endpoint for operational and security diagnostics. It is intended for local troubleshooting, monitoring agents and cluster operations. It is **disabled by default** and, when enabled without changing the allowlist, accepts only loopback clients.
+
+The endpoint is separate from the user-facing `/api/diagnostics/*` routes. It does not require a RustBox mailbox session. Instead, access requires **both**:
+
+1. the effective client IP to match `diagnostics_endpoint.allowed_networks`, and
+2. the configured diagnostics token or Basic Auth credentials.
+
+Requests from a non-allowed address receive HTTP `403`. Requests from an allowed address with missing/invalid diagnostics credentials receive HTTP `401`. Critical backend probe failures return HTTP `503`; healthy or degraded reports return HTTP `200` with `status` set to `ok` or `degraded`.
+
+## Configuration
+
+```toml
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "token" # token | basic
+# token = "replace-with-at-least-24-random-characters"
+# basic_username = "rustbox-monitor"
+# basic_password = "replace-with-a-long-random-password"
+include_user_identifiers = false
+probe_timeout_secs = 5
+security_window_secs = 900
+```
+
+`path` must remain below `/api/system/` so it cannot collide with normal application API routes.
+
+### Token authentication
+
+Prefer keeping the token outside TOML, for example in `.env` or an orchestrator secret:
+
+```bash
+DIAGNOSTICS_ENDPOINT__ENABLED=true
+DIAGNOSTICS_ENDPOINT__AUTH=token
+DIAGNOSTICS_ENDPOINT__TOKEN='a-long-random-secret-at-least-24-characters'
+```
+
+Example request:
+
+```bash
+curl -fsS \
+  -H "Authorization: Bearer $DIAGNOSTICS_TOKEN" \
+  http://127.0.0.1:3001/api/system/diagnostics
+```
+
+`X-RustBox-Diagnostics-Token` is accepted as an alternative to the Bearer header for monitoring systems that cannot set an `Authorization` header.
+
+### Basic authentication
+
+```toml
+[diagnostics_endpoint]
+enabled = true
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "basic"
+```
+
+```bash
+DIAGNOSTICS_ENDPOINT__BASIC_USERNAME='rustbox-monitor'
+DIAGNOSTICS_ENDPOINT__BASIC_PASSWORD='a-long-random-monitoring-password'
+```
+
+Basic Auth must only be used over HTTPS/TLS (directly or at a trusted reverse proxy), because the credentials are not encrypted by the Basic scheme itself.
+
+## Networks and reverse proxies
+
+The network allowlist accepts IPv4/IPv6 addresses and CIDRs. Single addresses may also be specified in TOML.
+
+Example monitoring network:
+
+```toml
+[diagnostics_endpoint]
+enabled = true
+allowed_networks = [
+  "127.0.0.1/32",
+  "::1/128",
+  "10.42.20.0/24",
+  "2001:db8:42::/64",
+]
+auth = "token"
+```
+
+For a reverse proxy, configure `trusted_proxies` separately. RustBox only accepts `X-Forwarded-For` for diagnostics when the directly connected proxy is trusted. If proxy headers arrive from an untrusted peer, diagnostics fails closed with HTTP `403` rather than treating the proxy address as the real client.
+
+```toml
+trusted_proxies = "127.0.0.1/32,10.42.0.0/16"
+
+[diagnostics_endpoint]
+enabled = true
+allowed_networks = ["10.42.20.0/24"]
+auth = "token"
+```
+
+A trusted proxy should provide a valid `X-Forwarded-For`. `Forwarded` or `X-Real-IP` without `X-Forwarded-For` is deliberately rejected for this endpoint. In production, also restrict the diagnostics path at the firewall, ingress or reverse-proxy layer.
+
+## Returned data
+
+The report contains:
+
+- application version, process uptime/start time and PID; host-wide CPU, memory, load-average and other machine statistics are deliberately not collected;
+- effective non-secret configuration and feature switches;
+- IMAP/SMTP/Sieve endpoint configuration without credentials;
+- SQL backend, engine version, query latency, account/schema versions, SQLite file size or SQL pool size/idle connection count;
+- session persistence health and aggregate active session/user/browser counts for SQL or Redis;
+- local-node cached sessions, timestamps and mail endpoints; e-mail/user hash identifiers appear only when `include_user_identifiers=true`;
+- filesystem/S3 configuration plus a live storage health probe;
+- Tantivy/OpenSearch configuration; OpenSearch adds cluster health, node/shard counts and index document count;
+- active IMAP IDLE task/subscriber counts;
+- request counters and a bounded in-memory security window for failed logins, access denials, rate-limit responses and server errors;
+- configuration warnings for risky settings such as disabled TLS verification, HTTP OpenSearch/S3, global diagnostics allowlists or production browser security headers being disabled.
+
+## Secret handling
+
+The endpoint never returns diagnostics credentials, mailbox passwords, session encryption keys, Redis passwords, S3 access/secret/session keys, OpenSearch passwords or full credential-bearing DSNs. URLs are reduced to scheme/host/port/path and query strings/userinfo are removed. Secret fields are represented only as `...Configured: true|false` where useful.
+
+`include_user_identifiers=false` is the default. With that setting, local session details omit e-mail addresses and stable user hashes while aggregate user/session counts remain visible.
+
+All endpoint responses, including `401` and `403`, carry `Cache-Control: no-store`, `Pragma: no-cache`, `X-Content-Type-Options: nosniff` and `Cross-Origin-Resource-Policy: same-origin` independently of the general browser security-header switch.
+
+## Security signals
+
+The telemetry buffer is bounded and in-memory; it stores only timestamp, event category, source IP and request path. It does **not** store credentials, Authorization headers, cookies, tokens, request bodies or mail content.
+
+Within `security_window_secs` the report includes counts and top source IPs for:
+
+- rejected login attempts;
+- HTTP `429` rate limiting;
+- HTTP `403` access denials;
+- HTTP `5xx` server failures;
+- denied diagnostics access.
+
+`bruteForceSignal` becomes true after repeated login rejection/rate-limit activity, while `diagnosticsAttackSignal` flags repeated attempts against the management endpoint. These are preliminary operational signals, not an IDS or an account-lockout mechanism. In a multi-node deployment the counters are node-local; aggregate application/security logs in a central monitoring/SIEM system for cluster-wide detection.
+
+## Process and host metrics
+
+The diagnostics endpoint deliberately avoids host-wide metrics and platform-specific process probes. It does not read `/proc`, query system CPU/RAM/load averages, enumerate host resources or add a system-information dependency. The portable process section is limited to the RustBox PID, while process uptime/start time and request/security counters come from RustBox's own in-memory runtime state. This keeps the endpoint low-overhead and portable across supported operating systems.
+
+## Probe cost
+
+The endpoint performs live backend checks, so it should not be polled at sub-second frequency:
+
+- SQL executes lightweight health/version/schema queries;
+- Redis uses `PING` plus bounded `SCAN`/`MGET` of at most 5000 session records and reports `truncated=true` if the cap is hit;
+- S3/filesystem health writes and deletes a tiny temporary `_health/...` object;
+- OpenSearch queries cluster health and the configured index count;
+- each backend probe has its own `probe_timeout_secs` timeout.
+
+A polling interval around tens of seconds is appropriate for typical monitoring. Use the normal `/api/health` or `/api/ready` endpoints for very frequent liveness/readiness checks.

migrations/README.md

@@ -1,6 +1,6 @@
 # Database schemas and migrations
 
-RustBox 0.2.6 keeps SQL, blob storage and search as independent concerns:
+RustBox 0.2.8 keeps SQL, blob storage and search as independent concerns:
 
 ```text
 database_backend = sqlite | mysql | pgsql
@@ -17,16 +17,19 @@ When `session_backend = "database"`, sessions live in the selected SQL database.
 migrations/
 ├── sqlite/
 │   ├── schema.sql
-│   └── V047__blob_keys_and_search_outbox.sql
+│   ├── V047__blob_keys_and_search_outbox.sql
+│   └── V048__folder_counter_generation.sql
 ├── mysql/
 │   ├── schema.sql
-│   └── V047__blob_keys_and_search_outbox.sql
+│   ├── V047__blob_keys_and_search_outbox.sql
+│   └── V048__folder_counter_generation.sql
 └── pgsql/
     ├── schema.sql
-    └── V047__blob_keys_and_search_outbox.sql
+    ├── V047__blob_keys_and_search_outbox.sql
+    └── V048__folder_counter_generation.sql
 ```
 
-Each `schema.sql` is the current complete schema for fresh installations. The historical compatibility baseline remains **V046**. RustBox 0.2.1 adds **V047**, which adds attachment SHA-256 metadata and the durable search outbox used by external indexing.
+Each `schema.sql` is the current complete schema for fresh installations. The historical compatibility baseline remains **V046**. RustBox 0.2.1 adds **V047**, which adds attachment SHA-256 metadata and the durable search outbox used by external indexing. RustBox 0.2.8 adds **V048**, which adds the monotonic `folders.counter_generation` used to reject stale IMAP counter writes even when the numeric counts temporarily return to an earlier value.
 
 Account data is isolated inside the selected physical database with a deterministic, collision-checked table prefix derived from the account hash. The `{{p}}` marker in tenant SQL is replaced by RustBox at provisioning/migration time. Sessions are global and therefore are not prefixed.
 
@@ -34,7 +37,7 @@ Account data is isolated inside the selected physical database with a determinis
 
 Every schema-changing release must add the same logical migration for all supported SQL engines and register it in `src/db/pool.rs`. Do not update only `schema.sql`: fresh installs use the baseline while existing installations use the numbered migration path.
 
-The next migration number after RustBox 0.2.6 is **V048**.
+The next migration number after RustBox 0.2.8 is **V049**.
 
 Redis and Redis Sentinel do not use SQL migrations.
 

migrations/mysql/V048__folder_counter_generation.sql

@@ -0,0 +1 @@
+ALTER TABLE {{p}}folders ADD COLUMN counter_generation BIGINT NOT NULL DEFAULT 0;

migrations/mysql/schema.sql

@@ -1,7 +1,7 @@
 -- RustBox 0.2.0 MySQL schema.
 -- One physical database contains global sessions plus isolated per-account tables.
 -- Application tables are materialized by replacing {{p}} with a collision-checked prefix.
--- Squashed compatibility baseline: V046. Current runtime schema: V047.
+-- Squashed compatibility baseline: V046. Current runtime schema: V048.
 
 -- RUSTBOX:GLOBAL-BEGIN
 CREATE TABLE IF NOT EXISTS rustbox_accounts (
@@ -247,6 +247,7 @@ CREATE TABLE {{p}}folders (
     unread_count BIGINT NOT NULL DEFAULT 0,
     uid_validity BIGINT NOT NULL DEFAULT 0,
     highest_modseq BIGINT NOT NULL DEFAULT 0,
+    counter_generation BIGINT NOT NULL DEFAULT 0,
     updated_at VARCHAR(64) NOT NULL DEFAULT (CAST(CURRENT_TIMESTAMP AS CHAR)),
     messages_updated_at VARCHAR(64)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

migrations/pgsql/V048__folder_counter_generation.sql

@@ -0,0 +1 @@
+ALTER TABLE {{p}}folders ADD COLUMN counter_generation BIGINT NOT NULL DEFAULT 0;

migrations/pgsql/schema.sql

@@ -1,7 +1,7 @@
 -- RustBox 0.2.0 PostgreSQL schema.
 -- One physical database contains global sessions plus isolated per-account tables.
 -- Application tables are materialized by replacing {{p}} with a collision-checked prefix.
--- Squashed compatibility baseline: V046. Current runtime schema: V047.
+-- Squashed compatibility baseline: V046. Current runtime schema: V048.
 
 -- RUSTBOX:GLOBAL-BEGIN
 CREATE TABLE IF NOT EXISTS rustbox_accounts (
@@ -248,6 +248,7 @@ CREATE TABLE {{p}}folders (
     unread_count BIGINT NOT NULL DEFAULT 0,
     uid_validity BIGINT NOT NULL DEFAULT 0,
     highest_modseq BIGINT NOT NULL DEFAULT 0,
+    counter_generation BIGINT NOT NULL DEFAULT 0,
     updated_at TEXT NOT NULL DEFAULT (CURRENT_TIMESTAMP::text),
     messages_updated_at TEXT
 );

migrations/sqlite/V048__folder_counter_generation.sql

@@ -0,0 +1 @@
+ALTER TABLE {{p}}folders ADD COLUMN counter_generation INTEGER NOT NULL DEFAULT 0;

migrations/sqlite/schema.sql

@@ -1,7 +1,7 @@
 -- RustBox 0.2.0 SQLite schema.
 -- One physical database contains global sessions plus isolated per-account tables.
 -- Application tables are materialized from the tenant section by replacing {{p}}.
--- Squashed compatibility baseline: V046. Current runtime schema: V047.
+-- Squashed compatibility baseline: V046. Current runtime schema: V048.
 
 -- RUSTBOX:GLOBAL-BEGIN
 CREATE TABLE IF NOT EXISTS rustbox_accounts (
@@ -184,6 +184,7 @@ CREATE TABLE {{p}}folders (
     unread_count  INTEGER NOT NULL DEFAULT 0,
     uid_validity  INTEGER NOT NULL DEFAULT 0,
     highest_modseq INTEGER NOT NULL DEFAULT 0,
+    counter_generation INTEGER NOT NULL DEFAULT 0,
     updated_at    TEXT NOT NULL DEFAULT (datetime('now')),
     messages_updated_at TEXT);
 

packaging/rustbox.toml

@@ -1,4 +1,4 @@
-# RustBox 0.2.6 - packaged production configuration (DEB/RPM)
+# RustBox 0.2.8 - packaged production configuration (DEB/RPM)
 #
 # This file contains all supported RustBox configuration options.
 # Commented options are optional and do not change the packaged defaults.
@@ -39,10 +39,8 @@ default_interface_skin = "apple-mail"
 sieve_enabled = true
 diagnostics_enabled = true
 about_enabled = true
-# Browser-facing CSP/frame/referrer/permissions headers. Off by default for compatibility.
+# Content-type-aware browser security headers. Off by default for compatibility.
 security_headers_enabled = false
-
-
 # -----------------------------------------------------------------------------
 # Database
 # -----------------------------------------------------------------------------
@@ -212,20 +210,6 @@ pgp_allow_private_export = true
 #
 # pgp_enabled = false
 
-
-# -----------------------------------------------------------------------------
-# Blob storage
-# -----------------------------------------------------------------------------
-#
-# Blob storage is independent from database_backend.
-#
-# PostgreSQL/MySQL can use a local filesystem in single-node mode.
-#
-# Cluster deployments must use:
-# - S3-compatible object storage, or
-# - a genuinely shared POSIX filesystem such as NFS/CephFS/GlusterFS.
-#
-
 [storage]
 
 # filesystem | s3
@@ -284,6 +268,23 @@ retry_timeout_secs = 60
 # kms_key_id = "..."
 
 
+# -----------------------------------------------------------------------------
+# IMAP synchronization / automatic body cache
+# -----------------------------------------------------------------------------
+
+[sync]
+
+# Periodic fallback/background IMAP reconciliation. Active folders use IMAP IDLE,
+# while this pass refreshes counters/flags/headers in the rest of the mailbox and
+# also runs automatic deep indexing when enabled. Lower values increase IMAP load.
+interval_secs = 30
+
+# Maximum full message bodies fetched from IMAP per periodic pass when deep index is
+# effective. Larger batches catch up faster but increase bandwidth, application database/
+# search-storage usage and indexing CPU/I/O bursts.
+deep_index_batch_size = 10
+
+
 # -----------------------------------------------------------------------------
 # Search
 # -----------------------------------------------------------------------------
@@ -327,6 +328,13 @@ allow_insecure_http = false
 
 request_timeout_secs = 10
 
+# Server-wide automatic full-body cache/index switch. Production default is false
+# because enabling it proactively downloads and stores full message bodies. When
+# true, all accounts are deep-indexed; when false, an account may still opt in via
+# its existing deep_index preference.
+deep_index = false
+
+# Search outbox worker cadence/batch; these do NOT control IMAP body downloads.
 worker_interval_secs = 2
 worker_batch_size = 100
 worker_max_attempts = 12
@@ -378,6 +386,7 @@ worker_max_attempts = 12
 # required = true
 # allow_insecure_http = false
 # request_timeout_secs = 10
+# deep_index = false
 # worker_interval_secs = 2
 # worker_batch_size = 100
 # worker_max_attempts = 12
@@ -430,4 +439,40 @@ worker_max_attempts = 12
 # ]
 # redis_sentinel_master = "mymaster"
 # redis_sentinel_password = "sentinel-secret"
-# redis_password = "secret"
+# redis_password = "secret"
+
+
+# -----------------------------------------------------------------------------
+# Blob storage
+# -----------------------------------------------------------------------------
+#
+# Blob storage is independent from database_backend.
+#
+# PostgreSQL/MySQL can use a local filesystem in single-node mode.
+#
+# Cluster deployments must use:
+# - S3-compatible object storage, or
+# - a genuinely shared POSIX filesystem such as NFS/CephFS/GlusterFS.
+#
+
+# -----------------------------------------------------------------------------
+# Administrator system diagnostics endpoint
+# -----------------------------------------------------------------------------
+# Disabled by default. When enabled, the endpoint performs live probes of SQL,
+# session persistence/Redis, filesystem/S3, Tantivy/OpenSearch and reports
+# process/runtime/IMAP-IDLE/security telemetry. Returned configuration is redacted:
+# passwords, auth tokens, S3 secrets, session keys and URL credentials are never emitted.
+# Access is an AND condition: source IP/CIDR must be allowed and token/basic auth must pass.
+[diagnostics_endpoint]
+enabled = false
+path = "/api/system/diagnostics"
+# Fail-safe default. Add only monitoring/admin networks that really need access.
+allowed_networks = ["127.0.0.1/32", "::1/128"]
+auth = "token" # token | basic
+# Prefer injecting these with a secret manager/environment rather than storing here.
+# token = "at-least-24-random-characters"
+# basic_username = "rustbox-monitor"
+# basic_password = "long-random-password"
+include_user_identifiers = false
+probe_timeout_secs = 5
+security_window_secs = 900

packaging/systemd/rustbox.service

@@ -8,7 +8,7 @@ Type=simple
 User=rustbox
 Group=rustbox
 Environment=RUSTBOX_CONFIG=/etc/rustbox/rustbox.toml
-#Environment=RUST_LOG=info
+#Environment=RUST_LOG=warn,rustbox=info,tower_http=info
 WorkingDirectory=/var/lib/rustbox
 ExecStart=/usr/local/bin/rustbox
 Restart=on-failure

scripts/validate-release-static.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""Static/offline release checks for RustBox 0.2.6.
+"""Static/offline release checks for RustBox 0.2.8.
 
 These checks intentionally avoid pretending to replace `cargo test`: they validate
 configuration, SQL migrations, Docker examples, query-catalog parity and release
@@ -49,14 +49,14 @@ def extract_section(text: str, begin: str, end: str) -> str:
 
 # Release/toolchain metadata.
 cargo = tomllib.loads(read("Cargo.toml"))
-require(cargo["package"]["version"] == "0.2.6", "Cargo package version is 0.2.6")
+require(cargo["package"]["version"] == "0.2.8", "Cargo package version is 0.2.8")
 require(cargo["package"]["rust-version"] == "1.99.1", "Cargo rust-version is 1.99.1")
 toolchain = tomllib.loads(read("rust-toolchain.toml"))
 require(toolchain["toolchain"]["channel"] == "1.99.1", "rust-toolchain pins Rust 1.99.1")
 require((ROOT / "Cargo.lock").is_file(), "Cargo.lock is retained for reproducible application builds")
 lock = tomllib.loads(read("Cargo.lock"))
 lock_rustbox = next((pkg for pkg in lock.get("package", []) if pkg.get("name") == "rustbox"), {})
-require(lock_rustbox.get("version") == "0.2.6", "Cargo.lock RustBox package version is 0.2.6")
+require(lock_rustbox.get("version") == "0.2.8", "Cargo.lock RustBox package version is 0.2.8")
 require("cargo generate-lockfile" in read("scripts/build-release.sh"), "release script generates Cargo.lock when missing")
 release_script = read("scripts/build-release.sh")
 release_script_flat = " ".join(release_script.replace("\\", " ").split())
@@ -69,14 +69,24 @@ require("make_zip.py" in package_script and "sha256sum" in package_script, "rele
 require("cargo generate-lockfile" in read(".github/workflows/ci.yml"), "CI regenerates Cargo.lock before --locked checks")
 require("validate-release-static.py" in read("scripts/build-release.sh"), "release script runs offline/static release gate")
 require("validate-release-static.py" in read(".github/workflows/ci.yml"), "CI runs offline/static release gate")
-require(read("README.md").startswith("# RustBox 0.2.6"), "README identifies RustBox 0.2.6")
+require(read("README.md").startswith("# RustBox 0.2.8"), "README identifies RustBox 0.2.8")
-require(read("RELEASE-MANIFEST.txt").startswith("RustBox 0.2.6"), "release manifest identifies RustBox 0.2.6")
+require(read("RELEASE-MANIFEST.txt").startswith("RustBox 0.2.8"), "release manifest identifies RustBox 0.2.8")
-require(read("RELEASE-VALIDATION.txt").startswith("RustBox 0.2.6"), "release validation identifies RustBox 0.2.6")
+require(read("RELEASE-VALIDATION.txt").startswith("RustBox 0.2.8"), "release validation identifies RustBox 0.2.8")
-require(read("docs/IMPLEMENTATION_STATUS.md").startswith("# RustBox 0.2.6"), "implementation status identifies RustBox 0.2.6")
+require(read("docs/IMPLEMENTATION_STATUS.md").startswith("# RustBox 0.2.8"), "implementation status identifies RustBox 0.2.8")
+require("V048" in read("RELEASE-MANIFEST.txt") and "V049" in read("RELEASE-MANIFEST.txt"), "release manifest documents V048 and reserves V049")
+require("V048" in read("migrations/README.md") and "V049" in read("migrations/README.md"), "migration guide documents V048 and reserves V049")
 require((ROOT / "docs/STORAGE_SEARCH_OPERATIONS.md").is_file(), "storage/search operations guide exists")
 require('imap_host = ""' not in read("config.dev.toml"), "development config does not override IMAP host with an invalid empty value")
 require(not re.search(r"(?m)^IMAP_HOST=\s*$", read(".env.example")), "environment example does not set an invalid empty IMAP host")
-require("pgp_enabled: bool" in read("src/routes/auth.rs"), "auth policy exposes OpenPGP availability")
+dev_sh = read("dev.sh")
+require('ENV_FILE="${RUSTBOX_ENV_FILE:-$ROOT/.env}"' in dev_sh and '. "$ENV_FILE"' in dev_sh, "development launcher loads project .env")
+require(dev_sh.find('. "$ENV_FILE"') < dev_sh.find('cargo run --quiet --bin rustbox -- --check-config'), "development launcher loads .env before config validation")
+require('warn,rustbox=debug,tower_http=info' in dev_sh, "development launcher keeps dependencies at WARN while RustBox stays DEBUG")
+require('case "${RUST_LOG:-}" in' in dev_sh and 'trace)' in dev_sh and 'info)' in dev_sh, "development launcher scopes legacy/simple global RUST_LOG levels")
+require('RUST_LOG=warn,rustbox=debug,tower_http=info' in read(".env.example"), "development environment example does not enable noisy dependency INFO logs")
+main_rs = read("src/main.rs")
+require('"debug" => "warn,rustbox=debug,tower_http=info"' in main_rs and 'EnvFilter::new(default_log_filter(log_level))' in main_rs, "config log_level controls RustBox verbosity without globally enabling dependency DEBUG/INFO")
+require("pub struct SessionPolicyResponse" in read("src/routes/auth.rs") and "pgp_enabled: bool" in read("src/routes/auth.rs"), "authenticated session policy exposes OpenPGP availability")
 require("setOpenPgpAvailability" in read("src/web/js/72-openpgp-identities.js"), "UI hides administratively disabled OpenPGP")
 storage_rs = read("src/storage/mod.rs")
 require(
@@ -95,9 +105,143 @@ config_rs = read("src/config.rs")
 routes_mod = read("src/routes/mod.rs")
 require("pub sieve_enabled: bool" in config_rs and "pub diagnostics_enabled: bool" in config_rs and "pub about_enabled: bool" in config_rs, "configuration exposes Sieve, diagnostics and About feature gates")
 require("pub security_headers_enabled: bool" in config_rs and "security_headers_enabled: false" in config_rs, "security headers are configurable and disabled by default")
+require("pub struct SyncConfig" in config_rs and "pub interval_secs: u64" in config_rs and "pub deep_index_batch_size: u32" in config_rs, "IMAP sync cadence and deep-index batch size are configurable")
+require("pub deep_index: bool" in config_rs and "deep_index: false" in config_rs, "server-wide automatic deep index is configurable and production-safe by default")
+system_diag_rs = read("src/routes/system_diagnostics.rs")
+session_rs = read("src/auth/session.rs")
+session_persistence_rs = read("src/session_store/mod.rs")
+require("pub struct DiagnosticsEndpointConfig" in config_rs and "pub diagnostics_endpoint: DiagnosticsEndpointConfig" in config_rs, "administrator diagnostics endpoint has a dedicated configuration block")
+require('default_diagnostics_allowed_networks' in config_rs and '"127.0.0.1/32"' in config_rs and '"::1/128"' in config_rs, "administrator diagnostics allowlist defaults to IPv4/IPv6 loopback")
+require('diagnostics_endpoint.path must be an absolute /api/system/' in config_rs and 'diagnostics_endpoint.token must contain at least 24 characters' in config_rs and 'diagnostics_endpoint.basic_password must contain at least 16 characters' in config_rs, "administrator diagnostics validates namespace and authentication strength")
+require('if config.diagnostics_endpoint.enabled' in routes_mod and 'get(system_diagnostics::system_diagnostics)' in routes_mod, "administrator diagnostics route is registered only when enabled")
+require('diagnostics_client_ip' in system_diag_rs and 'proxy headers received from an untrusted peer' in system_diag_rs, "administrator diagnostics fails closed on untrusted reverse-proxy headers")
+require('parsed_diagnostics_allowed_networks' in system_diag_rs and 'return forbidden();' in system_diag_rs, "administrator diagnostics enforces source IP/CIDR allowlist before probes")
+require('constant_time_secret_eq' in system_diag_rs and 'basic_credentials' in system_diag_rs and 'bearer_token' in system_diag_rs, "administrator diagnostics supports protected token and Basic authentication")
+require('HeaderValue::from_static("no-store")' in system_diag_rs and 'harden_diagnostics_response' in system_diag_rs, "administrator diagnostics responses are explicitly non-cacheable")
+require('"database": db_diag' in system_diag_rs and '"storage": {' in system_diag_rs and '"search": search_status' in system_diag_rs and '"sessions": {' in system_diag_rs, "administrator diagnostics reports database, storage, search and session state")
+require('bruteForceSignal' in system_diag_rs and 'diagnosticsAttackSignal' in system_diag_rs and 'MAX_SECURITY_EVENTS' in system_diag_rs, "administrator diagnostics includes bounded brute-force/access-denial telemetry")
+require('pub struct SessionPersistenceDiagnostics' in session_persistence_rs and 'diagnostics_snapshot' in session_rs, "administrator diagnostics reports local and persisted session state")
+require('user_hash: Option<String>' in session_rs and 'include_user_identifiers.then' in session_rs, "administrator diagnostics omits stable user identifiers unless explicitly enabled")
+require('schema_aligned: Option<bool>' in read("src/db/pool.rs") and 'expected_schema_version' in read("src/db/pool.rs"), "administrator diagnostics reports database schema alignment")
+require('connected_clients' in read("src/session_store/redis_store.rs") and 'used_memory_bytes' in read("src/session_store/redis_store.rs") and 'master_link_status' in read("src/session_store/redis_store.rs"), "administrator diagnostics reports Redis runtime INFO without credentials")
+require('"idleConnections"' in system_diag_rs and 'diagnostics_snapshot' in read("src/realtime/idle.rs"), "administrator diagnostics reports active IMAP IDLE connections")
+require('cluster_status.eq_ignore_ascii_case("green")' in read("src/search/engine.rs") and 'cluster_status.eq_ignore_ascii_case("red")' in read("src/search/engine.rs"), "administrator diagnostics treats OpenSearch health conservatively")
+require('middleware::from_fn(system_diagnostics::observe_requests)' in routes_mod and routes_mod.count('if config.diagnostics_endpoint.enabled') >= 2, "administrator diagnostics telemetry middleware is installed only when the endpoint is enabled")
+require('sanitize_url' in system_diag_rs and 'secretKeyConfigured' in system_diag_rs and 'passwordConfigured' in system_diag_rs and 'credentialConfigured' in system_diag_rs, "administrator diagnostics redacts configured credentials and DSN userinfo")
+require('/proc/' not in system_diag_rs and 'systemMemoryTotalKiB' not in system_diag_rs and 'loadAverage' not in system_diag_rs and 'availableProcessors' not in system_diag_rs, "administrator diagnostics avoids host-specific /proc and machine-wide resource metrics")
+require((ROOT / "docs/SYSTEM_DIAGNOSTICS.md").is_file() and "disabled by default" in read("docs/SYSTEM_DIAGNOSTICS.md") and "HTTP `403`" in read("docs/SYSTEM_DIAGNOSTICS.md"), "administrator diagnostics security and operations are documented")
 require("if config.sieve_enabled" in routes_mod and "if config.diagnostics_enabled" in routes_mod, "disabled Sieve and diagnostics routes are not registered")
 require(".fallback(|| async { axum::http::StatusCode::NOT_FOUND })" in routes_mod, "API namespace has an explicit 404 fallback before the SPA fallback")
 require("if config.security_headers_enabled" in routes_mod and "add_security_headers" in routes_mod, "security-header middleware is opt-in")
+ui_rs = read("src/ui.rs")
+pgp_rs = read("src/routes/pgp.rs")
+contacts_rs = read("src/routes/contacts.rs")
+require("X_CONTENT_TYPE_OPTIONS" not in ui_rs and "x-content-type-options" not in pgp_rs and "x-content-type-options" not in contacts_rs, "security headers are centralized behind the opt-in middleware")
+require("response_content_type_is" in routes_mod, "security-header middleware classifies response content types")
+require("headers.insert(\n        headers.insert(" not in routes_mod, "security-header middleware has no duplicated insert fragment")
+require("if is_html || is_css" in routes_mod, "Referrer-Policy is limited to HTML/CSS responses")
+require("if is_html {" in routes_mod, "document-only browser policies are limited to HTML responses")
+require("script-src 'self'; script-src-attr 'none'" in routes_mod, "HTML CSP permits only same-origin external scripts and disables script attributes")
+require("style-src 'self'; style-src-attr 'unsafe-inline'" in routes_mod and "style-src 'self' 'unsafe-inline'" not in routes_mod, "HTML CSP limits unsafe-inline to dynamic style attributes rather than stylesheet blocks")
+require("sha256-" not in routes_mod and "script-src 'self' 'unsafe-inline'" not in routes_mod, "HTML CSP does not rely on inline-script hashes or unsafe-inline")
+require('headers.insert(header::CACHE_CONTROL, HeaderValue::from_static("no-store"))' in routes_mod, "API security middleware forces private responses to no-store")
+require(
+    "HeaderValue::from_static(\"frame-ancestors 'none'\")" in routes_mod
+    and 'headers.insert("x-frame-options", HeaderValue::from_static("DENY"))' in routes_mod,
+    "browser API security profile includes explicit frame denial",
+)
+html_security_start = routes_mod.find("if is_html {")
+html_security_end = routes_mod.find("\n    response", html_security_start)
+require(
+    html_security_start >= 0
+    and html_security_end > html_security_start
+    and routes_mod.count('"permissions-policy"') == 1
+    and routes_mod.count('"cross-origin-opener-policy"') == 1
+    and html_security_start < routes_mod.find('"permissions-policy"') < html_security_end
+    and html_security_start < routes_mod.find('"cross-origin-opener-policy"') < html_security_end,
+    "API security profile keeps Permissions-Policy and COOP on documents only",
+)
+require('"cross-origin-resource-policy"' in routes_mod and 'HeaderValue::from_static("same-origin")' in routes_mod, "security middleware applies same-origin CORP where appropriate")
+route_tests = read("src/routes/tests.rs")
+auth_routes = read("src/routes/auth.rs")
+auth_js = read("src/web/js/20-preferences-auth.js")
+require("security_headers_are_opt_in_and_content_type_aware" in route_tests, "security-header regression test covers content-type-aware behavior")
+require("auth_policy_exposes_only_login_requirements_before_authentication" in route_tests, "public auth-policy minimization has a regression test")
+require("pub struct SessionPolicyResponse" in auth_routes and '.route("/session-policy", get(auth::session_policy))' in routes_mod, "feature policy is exposed only behind the authenticated session route")
+require('request("/auth/session-policy"' in auth_js and "async function loadSessionPolicy()" in auth_js, "frontend loads optional feature policy only after authentication")
+require("script-src 'self' 'unsafe-inline'" in route_tests, "security regression test explicitly rejects unsafe-inline script policy")
+security_test_start = route_tests.find("async fn security_headers_are_opt_in_and_content_type_aware()")
+security_test_end = route_tests.find("\n#[tokio::test]", security_test_start + 1)
+security_test = route_tests[security_test_start:security_test_end]
+require(
+    'api.headers()["content-security-policy"]' in security_test
+    and "frame-ancestors 'none'" in security_test
+    and 'api.headers()["x-frame-options"]' in security_test
+    and '"DENY"' in security_test,
+    "API regression test enforces browser-facing anti-framing headers",
+)
+require(
+    'api.headers().get("permissions-policy").is_none()' in route_tests
+    and 'api.headers().get("cross-origin-opener-policy").is_none()' in route_tests,
+    "API regression test omits HTML-only Permissions-Policy and COOP",
+)
+imap_client_rs = read("src/imap/client.rs")
+idle_rs = read("src/realtime/idle.rs")
+realtime_sync_rs = read("src/realtime/sync.rs")
+require("config.sync.interval_secs" in realtime_sync_rs and "SYNC_INTERVAL_SECS" not in realtime_sync_rs, "periodic IMAP sync interval comes from configuration")
+require("config.sync.deep_index_batch_size" in realtime_sync_rs and "DEEP_INDEX_BATCH" not in realtime_sync_rs, "automatic body-cache batch size comes from configuration")
+require("config.search.deep_index" in realtime_sync_rs and "force_deep_index" in realtime_sync_rs, "server-wide deep-index setting participates in effective account behavior")
+messages_route_rs = read("src/routes/messages/mod.rs")
+folders_route_rs = read("src/routes/folders.rs")
+folders_js = read("src/web/js/30-folders-tags.js")
+reader_js = read("src/web/js/40-messages-reader.js")
+realtime_js = read("src/web/js/80-settings-realtime.js")
+require('uid_search("UNSEEN")' in imap_client_rs and "folder_status_extended_on_session" in imap_client_rs, "IMAP folder status has an authoritative UNSEEN search fallback")
+require('uid_search("UNSEEN")' in idle_rs and "server_unseen" in idle_rs, "IDLE reconciliation counts unseen UIDs instead of using SELECT UNSEEN as a count")
+require("tracing::info!(\n                        tracing::info!(" not in idle_rs, "IDLE handler has no duplicated tracing macro fragment")
+require("set_folder_counts" in realtime_sync_rs and "status.unseen != folder.unread_count" in realtime_sync_rs, "periodic sync repairs server folder counters before fast-path skips")
+require("MailEvent::FolderStatus" in messages_route_rs and "MessageFlagChange" in messages_route_rs, "message flag mutations publish targeted flag and folder-status events")
+folder_counts_route_rs = read("src/routes/folder_counts.rs")
+folders_db_rs = read("src/db/folders.rs")
+require("pub counter_generation: u64" in folders_db_rs and "expected_generation: u64" in folders_db_rs, "folder counter CAS uses a monotonic database generation")
+require("counter_generation_blocks_aba_stale_writer" in folders_db_rs, "folder counter generation has an ABA stale-writer regression test")
+require("set_folder_counts_if_unchanged" in folder_counts_route_rs and "for attempt in 0..2" in folder_counts_route_rs, "post-mutation folder counters use CAS with a fresh STATUS retry")
+require("reconcile_after_mutation" in messages_route_rs and "counter_snapshot" in messages_route_rs, "message mutations reconcile authoritative counters without stale overwrites")
+folder_mgmt_rs = read("src/routes/folder_mgmt.rs")
+require("reconcile_after_mutation" in folder_mgmt_rs, "mark-all-read uses the race-safe counter reconciler")
+require("get_all_uids_and_flags" in folder_mgmt_rs and "through_uid" in folder_mgmt_rs, "mark-all-read snapshots a UID cutoff so later arrivals stay unread locally")
+require("cached_uids" in folder_mgmt_rs and "for uid in &cached_uids" in folder_mgmt_rs, "empty-folder cleanup removes only messages captured before the server mutation")
+require("routes_folder_mgmt::Q_002" not in folder_mgmt_rs, "mark-all-read no longer blindly overwrites unread counters with zero")
+require("set_folder_counts_if_unchanged" in folders_route_rs, "forced folder refresh protects authoritative counters with compare-and-set")
+require("folder_statuses_extended" in folders_route_rs and "pending_sync_count" in folders_route_rs, "folder refresh batches authoritative IMAP status and exposes sync backlog")
+require("folder_refresh_uses_server_counts_without_relisting_fresh_folder_tree" in route_tests, "folder refresh regression test covers stale unread count versus authoritative IMAP STATUS")
+require("if !cache_fresh" in folders_route_rs and "if query.refresh || !cache_fresh" in folders_route_rs, "folder tree LIST uses TTL while forced refresh updates counters through STATUS")
+require("is_noselect" in folders_route_rs and "is_noselect" in realtime_sync_rs, "folder status refresh skips IMAP N\\Noselect hierarchy nodes")
+require("folder-count-wide" in folders_js and "folder-count-compact" in folders_js, "folder UI exposes responsive total/unread counters")
+index_html = read("src/web/index.html")
+require(index_html.find('id="indexing-indicator"') < index_html.find('id="contacts-btn"'), "synchronization/index activity indicator is positioned left of Contacts")
+require("folder-separator" in folders_js and ".folder-count .folder-separator" in read("src/web/css/30-mail.css"), "folder total/unread separator is styled independently from the unread value")
+require("#message-count" in folders_js and "folderName === state.folder" in folders_js, "authoritative folder totals update the active-folder message count without a list rerender")
+require("applyLocalMessageFlags" in reader_js and "updateMessageRowState" in reader_js, "reader flag updates patch individual message rows")
+require("applyOptimisticMessageFlag" in reader_js and "rollback = applyOptimisticMessageFlag" in reader_js, "read/unread actions update rows and counters optimistically with guarded rollback")
+require("if (payload.eventId)" in realtime_js and "const duplicate = state.realtimeSeenEvents.has(idKey);" in realtime_js and realtime_js.find("if (payload.eventId)") < realtime_js.find("const fingerprint ="), "realtime event dedupe trusts unique eventId before fingerprint fallback")
+require("\"eventId\": uuid::Uuid::new_v4().to_string()" in read("src/realtime/ws.rs"), "websocket envelopes carry unique eventId values for lossless client dedupe")
+require("MailEvent::FolderAllRead" in read("src/routes/folder_mgmt.rs") and "applyRealtimeFolderAllRead" in realtime_js, "mark-all-read propagates as a targeted realtime event instead of forcing a list reload")
+require("update_folder_sync_cursor" in read("src/db/folders.rs") and "Q_031" in read("src/queries/sqlite/queries.rs"), "folder flag-sync cursor is stored independently from authoritative counters")
+require('uid_fetch("1:*", "UID FLAGS")' in idle_rs and idle_rs.count("complete.then_some") >= 3, "IDLE fallback reconciles flags and rejects partial IMAP streams")
+require(re.search(r"index_message_with_connection\s*\(\s*&transaction", idle_rs) is not None, "IDLE header ingestion enqueues search indexing in the same database transaction")
+require("delete_folder_messages(&transaction" in messages_route_rs and "db::header_sync::invalidate(&transaction)" in messages_route_rs and re.search(r"update_folder_sync_status\s*\(\s*&transaction", messages_route_rs) is not None, "UIDVALIDITY reset keeps cache invalidation and folder metadata in one database transaction")
+require(
+    "db::folders::get_folder(conn, &status_name)" in messages_route_rs
+    and "total_count: folder_state.total_count" in messages_route_rs
+    and "unread_count: folder_state.unread_count" in messages_route_rs,
+    "background sync publishes committed folder counters instead of stale network snapshots",
+)
+require("IMAP cache incomplete" in realtime_js and "Search indexing" in realtime_js, "activity indicator reports IMAP cache and search-index backlog")
+require('indicator.classList.toggle("hidden", !busy)' in realtime_js, "activity indicator is hidden whenever synchronization/indexing is idle")
+require("setIndexingIndicator(true, 0)" in realtime_js and "setIndexingIndicator(false, 0)" in realtime_js, "manual search reindex drives the activity indicator immediately")
+require("MailEvent::IndexingStatus" in read("src/routes/diagnostics.rs") and "Extension(event_bus): Extension<Arc<EventBus>>" in read("src/routes/diagnostics.rs"), "manual search reindex broadcasts indexing activity to connected tabs")
+require("deep_index_enabled" in read("src/routes/diagnostics.rs") and "body cache disabled" in realtime_js, "search diagnostics explain whether automatic body caching is enabled")
 require('.route("/settings/reset", post(settings::reset_all_settings))' in routes_mod, "authenticated settings reset route is registered")
 require("db::settings::reset_all" in read("src/routes/settings.rs"), "settings reset route delegates preference reset to the DB layer")
 require('$("#quick-filter-btn")?.classList.toggle("hidden", state.authPolicy.sieveEnabled === false)' in read("src/web/js/20-preferences-auth.js"), "Sieve quick-filter UI disappears when Sieve is disabled")
@@ -233,11 +377,41 @@ require(pg_s3["storage"]["backend"] == "s3" and pg_s3["search"]["backend"] == "o
 require(my_nfs["cluster_mode"] is True and "data_dir" not in my_nfs, "MySQL/NFS cluster config omits data_dir")
 require(my_nfs["storage"]["backend"] == "filesystem" and my_nfs["storage"]["shared"] is True, "MySQL cluster marks POSIX/NFS storage shared")
 require(my_nfs["search"]["backend"] == "opensearch", "MySQL/NFS cluster uses OpenSearch")
+dev_config = tomllib.loads(read("config.dev.toml"))
+prod_config = tomllib.loads(read("config.example.toml"))
+packaged_config = tomllib.loads(read("packaging/rustbox.toml"))
+require(dev_config["search"]["deep_index"] is True, "development config enables automatic full-body cache/index")
+require(prod_config["search"]["deep_index"] is False and packaged_config["search"]["deep_index"] is False, "production configs keep automatic full-body cache/index disabled")
+require(prod_config.get("pgp_enabled") is True and "pgp_enabled" not in prod_config.get("search", {}), "production example keeps root-level settings outside TOML search table")
+require(packaged_config.get("database_backend") == "sqlite" and packaged_config.get("max_attachment_size_mb") == 50 and packaged_config.get("sieve_tls_mode") == "none" and "database_backend" not in packaged_config.get("search", {}), "packaged production config preserves top-level runtime settings outside TOML search table")
+for diagnostics_config in [
+    "config.dev.toml",
+    "config.example.toml",
+    "packaging/rustbox.toml",
+    "docker/configs/single-sqlite.toml",
+    "docker/configs/postgres-s3-opensearch.toml",
+    "docker/configs/ha-garage.toml",
+    "docker/configs/mysql-nfs-opensearch.toml",
+]:
+    parsed = tomllib.loads(read(diagnostics_config))
+    diagnostics = parsed.get("diagnostics_endpoint", {})
+    require(
+        diagnostics.get("enabled") is False
+        and diagnostics.get("allowed_networks") == ["127.0.0.1/32", "::1/128"]
+        and diagnostics.get("path") == "/api/system/diagnostics",
+        f"diagnostics config is disabled and loopback-only by default: {diagnostics_config}",
+    )
+require(dev_config["sync"]["interval_secs"] == 30 and dev_config["sync"]["deep_index_batch_size"] == 10, "development config documents 30s/10-message sync defaults")
+require(prod_config["sync"]["interval_secs"] == 30 and prod_config["sync"]["deep_index_batch_size"] == 10, "production example documents 30s/10-message sync defaults")
+require(packaged_config["sync"]["interval_secs"] == 30 and packaged_config["sync"]["deep_index_batch_size"] == 10, "packaged production config documents 30s/10-message sync defaults")
 ha = tomllib.loads(read("docker/configs/ha-garage.toml"))
 require(ha["cluster_mode"] is True and ha["session_backend"] == "redis", "HA/Garage config enables cluster mode with Redis-compatible sessions")
 require(ha["redis_url"] == "redis://valkey:6379/", "HA/Garage config targets Valkey for shared sessions")
 require(ha["storage"]["backend"] == "s3" and ha["storage"]["endpoint"] == "http://garage:3900", "HA/Garage config stores blobs in Garage S3")
 require(ha["search"]["backend"] == "opensearch", "HA/Garage config uses OpenSearch")
+require(ha["search"]["deep_index"] is True, "development HA example enables automatic deep index")
+require(single["search"]["deep_index"] is False and pg_s3["search"]["deep_index"] is False and my_nfs["search"]["deep_index"] is False, "production Docker configs disable automatic full-body cache/index by default")
+require(all(cfg["sync"]["interval_secs"] > 0 and cfg["sync"]["deep_index_batch_size"] > 0 for cfg in (single, pg_s3, my_nfs, ha)), "Docker configs provide positive IMAP sync/deep-index tuning values")
 dockerfile = read("docker/Dockerfile")
 require("FROM rust:1.99.1-trixie AS builder" in dockerfile, "Docker builder pins Rust 1.99.1 on Debian Trixie")
 require("FROM debian:trixie-slim" in dockerfile, "Docker runtime uses Debian Trixie slim")
@@ -295,6 +469,8 @@ try:
     require(outbox is not None, "fresh SQLite schema has search_outbox")
     outbox_columns = {row[1] for row in conn.execute("PRAGMA table_info(u_test__search_outbox)")}
     require("claimed_until" in outbox_columns, "fresh SQLite search_outbox separates worker lease from retry availability")
+    folder_columns = {row[1] for row in conn.execute("PRAGMA table_info(u_test__folders)")}
+    require("counter_generation" in folder_columns, "fresh SQLite schema has V048 folder counter generation")
     sqlite_header_sync = "INSERT INTO u_test__user_meta (key, value) VALUES ('header_sync_generation', '1') ON CONFLICT(key) DO UPDATE SET value = CAST(value AS INTEGER) + 1"
     conn.execute(sqlite_header_sync)
     conn.execute(sqlite_header_sync)
@@ -338,10 +514,44 @@ try:
 except Exception as exc:
     errors.append(f"SQLite V047 migration execution failed: {exc}")
 
+# V048 upgrade execution from a V047-style folders table, preserving existing counters.
+try:
+    conn = sqlite3.connect(":memory:")
+    conn.executescript(
+        "CREATE TABLE u_test__folders ("
+        "name TEXT PRIMARY KEY, delimiter TEXT, parent TEXT, flags TEXT NOT NULL DEFAULT '', "
+        "is_subscribed INTEGER NOT NULL DEFAULT 1, total_count INTEGER NOT NULL DEFAULT 0, "
+        "unread_count INTEGER NOT NULL DEFAULT 0, uid_validity INTEGER NOT NULL DEFAULT 0, "
+        "highest_modseq INTEGER NOT NULL DEFAULT 0, updated_at TEXT NOT NULL, messages_updated_at TEXT);"
+        "INSERT INTO u_test__folders "
+        "(name, total_count, unread_count, uid_validity, highest_modseq, updated_at) VALUES "
+        "('INBOX', 3444, 12, 77, 9001, '2026-11-01T00:00:00Z');"
+    )
+    migration = read("migrations/sqlite/V048__folder_counter_generation.sql").replace("{{p}}", "u_test__")
+    conn.executescript(migration)
+    columns = {row[1] for row in conn.execute("PRAGMA table_info(u_test__folders)")}
+    require("counter_generation" in columns, "V048 adds counter_generation to SQLite folders")
+    row = conn.execute(
+        "SELECT name, total_count, unread_count, uid_validity, highest_modseq, counter_generation "
+        "FROM u_test__folders WHERE name='INBOX'"
+    ).fetchone()
+    require(
+        row == ('INBOX', 3444, 12, 77, 9001, 0),
+        "V048 preserves existing folder counters and initializes generation at zero",
+    )
+    conn.close()
+except Exception as exc:
+    errors.append(f"SQLite V048 migration execution failed: {exc}")
+
 # Migration/query parity across SQL engines.
 for dialect in ("sqlite", "mysql", "pgsql"):
     require((ROOT / f"migrations/{dialect}/V047__blob_keys_and_search_outbox.sql").is_file(), f"V047 migration exists for {dialect}")
+    require((ROOT / f"migrations/{dialect}/V048__folder_counter_generation.sql").is_file(), f"V048 migration exists for {dialect}")
+    schema_text = read(f"migrations/{dialect}/schema.sql")
+    require("Current runtime schema: V048" in schema_text and "counter_generation" in schema_text, f"fresh {dialect} schema includes V048 folder counter generation")
     queries = read(f"src/queries/{dialect}/queries.rs")
+    folder_block = re.search(r"pub mod db_folders\s*\{(.*?)\n\}", queries, re.S)
+    require(folder_block is not None and "Q_032" in folder_block.group(1) and "counter_generation = counter_generation + 1" in folder_block.group(1), f"folder counter CAS increments generation for {dialect}")
     block_match = re.search(r"pub mod db_search_outbox\s*\{(.*?)\n\}", queries, re.S)
     require(block_match is not None, f"search outbox query module exists for {dialect}")
     if block_match:
@@ -351,6 +561,7 @@ for dialect in ("sqlite", "mysql", "pgsql"):
 pool = read("src/db/pool.rs")
 for dialect in ("SQLITE", "MYSQL", "PGSQL"):
     require(f"{dialect}_MIGRATIONS" in pool and "V047__blob_keys_and_search_outbox.sql" in pool, f"runtime migration catalog includes V047 ({dialect.lower()})")
+    require(f"{dialect}_MIGRATIONS" in pool and "V048__folder_counter_generation.sql" in pool, f"runtime migration catalog includes V048 ({dialect.lower()})")
 require("const BASE_SCHEMA_VERSION: u32 = 46" in pool, "legacy squashed baseline stays V046")
 require("latest_schema_version" in pool, "runtime schema version is computed from migrations")
 require(

src/auth/session.rs

@@ -1,3 +1,4 @@
+use std::collections::HashSet;
 use std::sync::Arc;
 use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 
@@ -5,9 +6,10 @@ use base64::Engine;
 use base64::engine::general_purpose::URL_SAFE_NO_PAD;
 use dashmap::DashMap;
 use rand::RngCore;
+use serde::Serialize;
 
 use crate::session_store::crypto::SessionCrypto;
-use crate::session_store::{PersistedSession, SessionPersistence};
+use crate::session_store::{PersistedSession, SessionPersistence, SessionPersistenceDiagnostics};
 
 pub type SessionId = String;
 pub type BrowserId = String;
@@ -54,6 +56,29 @@ pub struct AccountSession {
     pub user_agent: String,
 }
 
+#[derive(Debug, Clone, Serialize)]
+pub struct DiagnosticSession {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub email: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub user_hash: Option<String>,
+    pub imap_host: String,
+    pub imap_port: u16,
+    pub smtp_host: String,
+    pub smtp_port: u16,
+    pub created_at_unix: u64,
+    pub last_accessed_unix: u64,
+    pub user_agent: String,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct SessionStoreDiagnostics {
+    pub local_cached_sessions: usize,
+    pub local_cached_browsers: usize,
+    pub local_unique_users: usize,
+    pub sessions: Vec<DiagnosticSession>,
+}
+
 #[derive(Clone)]
 pub struct SessionStore {
     sessions: Arc<DashMap<SessionId, AccountSession>>,
@@ -480,6 +505,34 @@ impl SessionStore {
         self.sessions.is_empty()
     }
 
+    pub fn diagnostics_snapshot(&self, include_user_identifiers: bool) -> SessionStoreDiagnostics {
+        let mut users = HashSet::new();
+        let mut sessions = Vec::new();
+        for entry in self.sessions.iter() {
+            let session = entry.value();
+            users.insert(session.user_hash.clone());
+            sessions.push(DiagnosticSession {
+                email: include_user_identifiers.then(|| session.email.clone()),
+                user_hash: include_user_identifiers.then(|| session.user_hash.clone()),
+                imap_host: session.imap_host.clone(),
+                imap_port: session.imap_port,
+                smtp_host: session.smtp_host.clone(),
+                smtp_port: session.smtp_port,
+                created_at_unix: session.created_at_unix,
+                last_accessed_unix: session.last_accessed_unix,
+                user_agent: session.user_agent.chars().take(256).collect(),
+            });
+        }
+        sessions.sort_by_key(|session| std::cmp::Reverse(session.last_accessed_unix));
+        sessions.truncate(100);
+        SessionStoreDiagnostics {
+            local_cached_sessions: self.sessions.len(),
+            local_cached_browsers: self.browsers.len(),
+            local_unique_users: users.len(),
+            sessions,
+        }
+    }
+
     fn cache_persisted(&self, record: &PersistedSession) -> Result<AccountSession, String> {
         let crypto = self
             .crypto
@@ -747,6 +800,14 @@ impl SessionStore {
         removed
     }
 
+    pub async fn persistence_diagnostics(&self) -> Result<SessionPersistenceDiagnostics, String> {
+        let persistence = self
+            .persistence
+            .as_ref()
+            .ok_or_else(|| "session persistence is not configured".to_string())?;
+        persistence.diagnostics(Self::unix_now()).await
+    }
+
     pub async fn purge_expired_shared(&self) {
         self.purge_expired();
         if let Some(persistence) = self.persistence.as_ref()

src/config.rs

@@ -4,7 +4,7 @@ use figment::{
     Figment,
     providers::{Env, Format, Toml},
 };
-use ipnet::IpNet;
+use ipnet::{IpNet, Ipv4Net, Ipv6Net};
 use serde::Deserialize;
 
 #[derive(Debug, Deserialize, Clone)]
@@ -72,6 +72,64 @@ impl Default for StorageConfig {
     }
 }
 
+#[derive(Debug, Deserialize, Clone)]
+pub struct SyncConfig {
+    #[serde(default = "default_sync_interval_secs")]
+    pub interval_secs: u64,
+    #[serde(default = "default_deep_index_batch_size")]
+    pub deep_index_batch_size: u32,
+}
+
+impl Default for SyncConfig {
+    fn default() -> Self {
+        Self {
+            interval_secs: default_sync_interval_secs(),
+            deep_index_batch_size: default_deep_index_batch_size(),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize, Clone)]
+pub struct DiagnosticsEndpointConfig {
+    #[serde(default)]
+    pub enabled: bool,
+    #[serde(default = "default_diagnostics_endpoint_path")]
+    pub path: String,
+    #[serde(default = "default_diagnostics_allowed_networks")]
+    pub allowed_networks: Vec<String>,
+    #[serde(default = "default_diagnostics_auth_mode")]
+    pub auth: String,
+    #[serde(default)]
+    pub token: Option<String>,
+    #[serde(default)]
+    pub basic_username: Option<String>,
+    #[serde(default)]
+    pub basic_password: Option<String>,
+    #[serde(default)]
+    pub include_user_identifiers: bool,
+    #[serde(default = "default_diagnostics_probe_timeout_secs")]
+    pub probe_timeout_secs: u64,
+    #[serde(default = "default_diagnostics_security_window_secs")]
+    pub security_window_secs: u64,
+}
+
+impl Default for DiagnosticsEndpointConfig {
+    fn default() -> Self {
+        Self {
+            enabled: false,
+            path: default_diagnostics_endpoint_path(),
+            allowed_networks: default_diagnostics_allowed_networks(),
+            auth: default_diagnostics_auth_mode(),
+            token: None,
+            basic_username: None,
+            basic_password: None,
+            include_user_identifiers: false,
+            probe_timeout_secs: default_diagnostics_probe_timeout_secs(),
+            security_window_secs: default_diagnostics_security_window_secs(),
+        }
+    }
+}
+
 #[derive(Debug, Deserialize, Clone)]
 pub struct SearchConfig {
     #[serde(default = "default_search_backend")]
@@ -92,6 +150,8 @@ pub struct SearchConfig {
     pub allow_insecure_http: bool,
     #[serde(default = "default_search_request_timeout_secs")]
     pub request_timeout_secs: u64,
+    #[serde(default)]
+    pub deep_index: bool,
     #[serde(default = "default_search_worker_interval_secs")]
     pub worker_interval_secs: u64,
     #[serde(default = "default_search_worker_batch_size")]
@@ -112,6 +172,7 @@ impl Default for SearchConfig {
             required: false,
             allow_insecure_http: false,
             request_timeout_secs: default_search_request_timeout_secs(),
+            deep_index: false,
             worker_interval_secs: default_search_worker_interval_secs(),
             worker_batch_size: default_search_worker_batch_size(),
             worker_max_attempts: default_search_worker_max_attempts(),
@@ -197,6 +258,12 @@ pub struct AppConfig {
     #[serde(default)]
     pub search: SearchConfig,
 
+    #[serde(default)]
+    pub sync: SyncConfig,
+
+    #[serde(default)]
+    pub diagnostics_endpoint: DiagnosticsEndpointConfig,
+
     #[serde(default = "default_session_timeout_hours")]
     pub session_timeout_hours: u64,
 
@@ -363,6 +430,34 @@ fn default_search_request_timeout_secs() -> u64 {
     10
 }
 
+fn default_sync_interval_secs() -> u64 {
+    30
+}
+
+fn default_deep_index_batch_size() -> u32 {
+    10
+}
+
+fn default_diagnostics_endpoint_path() -> String {
+    "/api/system/diagnostics".to_string()
+}
+
+fn default_diagnostics_allowed_networks() -> Vec<String> {
+    vec!["127.0.0.1/32".to_string(), "::1/128".to_string()]
+}
+
+fn default_diagnostics_auth_mode() -> String {
+    "token".to_string()
+}
+
+fn default_diagnostics_probe_timeout_secs() -> u64 {
+    5
+}
+
+fn default_diagnostics_security_window_secs() -> u64 {
+    900
+}
+
 fn default_search_worker_interval_secs() -> u64 {
     2
 }
@@ -479,6 +574,8 @@ impl Default for AppConfig {
             cluster_mode: false,
             storage: StorageConfig::default(),
             search: SearchConfig::default(),
+            sync: SyncConfig::default(),
+            diagnostics_endpoint: DiagnosticsEndpointConfig::default(),
             session_timeout_hours: default_session_timeout_hours(),
             remember_me_enabled: default_remember_me_enabled(),
             remember_me_days: default_remember_me_days(),
@@ -565,6 +662,30 @@ impl AppConfig {
             .collect()
     }
 
+    pub fn parsed_diagnostics_allowed_networks(&self) -> Result<Vec<IpNet>, String> {
+        self.diagnostics_endpoint
+            .allowed_networks
+            .iter()
+            .map(|entry| {
+                let trimmed = entry.trim();
+                if let Ok(network) = trimmed.parse::<IpNet>() {
+                    return Ok(network);
+                }
+                let ip = trimmed
+                    .parse::<IpAddr>()
+                    .map_err(|e| format!("invalid diagnostics allowed network '{trimmed}': {e}"))?;
+                Ok(match ip {
+                    IpAddr::V4(value) => {
+                        IpNet::V4(Ipv4Net::new(value, 32).expect("valid IPv4 prefix"))
+                    }
+                    IpAddr::V6(value) => {
+                        IpNet::V6(Ipv6Net::new(value, 128).expect("valid IPv6 prefix"))
+                    }
+                })
+            })
+            .collect()
+    }
+
     pub fn parsed_outgoing_headers(&self) -> Result<Vec<(String, String)>, String> {
         const RESERVED: &[&str] = &[
             "from",
@@ -743,6 +864,86 @@ impl AppConfig {
                 return Err("Redis sessions require REDIS_URL or REDIS_SENTINEL_NODES + REDIS_SENTINEL_MASTER".to_string());
             }
         }
+        if self.diagnostics_endpoint.enabled {
+            let path = self.diagnostics_endpoint.path.trim();
+            if !path.starts_with("/api/system/") || path.contains('?') || path.contains('#') {
+                return Err("diagnostics_endpoint.path must be an absolute /api/system/... path without query/fragment".to_string());
+            }
+            if self.diagnostics_endpoint.allowed_networks.is_empty() {
+                return Err(
+                    "diagnostics_endpoint.allowed_networks cannot be empty when enabled"
+                        .to_string(),
+                );
+            }
+            self.parsed_diagnostics_allowed_networks()?;
+            if self.diagnostics_endpoint.probe_timeout_secs == 0
+                || self.diagnostics_endpoint.probe_timeout_secs > 60
+            {
+                return Err(
+                    "diagnostics_endpoint.probe_timeout_secs must be between 1 and 60".to_string(),
+                );
+            }
+            if self.diagnostics_endpoint.security_window_secs < 60
+                || self.diagnostics_endpoint.security_window_secs > 86_400
+            {
+                return Err(
+                    "diagnostics_endpoint.security_window_secs must be between 60 and 86400"
+                        .to_string(),
+                );
+            }
+            match self
+                .diagnostics_endpoint
+                .auth
+                .trim()
+                .to_ascii_lowercase()
+                .as_str()
+            {
+                "token" => {
+                    let token = self
+                        .diagnostics_endpoint
+                        .token
+                        .as_deref()
+                        .map(str::trim)
+                        .filter(|value| !value.is_empty())
+                        .ok_or("diagnostics_endpoint.token is required when auth=token")?;
+                    if token.len() < 24 {
+                        return Err(
+                            "diagnostics_endpoint.token must contain at least 24 characters"
+                                .to_string(),
+                        );
+                    }
+                }
+                "basic" => {
+                    let username = self
+                        .diagnostics_endpoint
+                        .basic_username
+                        .as_deref()
+                        .map(str::trim)
+                        .filter(|value| !value.is_empty())
+                        .ok_or("diagnostics_endpoint.basic_username is required when auth=basic")?;
+                    let password = self
+                        .diagnostics_endpoint
+                        .basic_password
+                        .as_deref()
+                        .filter(|value| !value.is_empty())
+                        .ok_or("diagnostics_endpoint.basic_password is required when auth=basic")?;
+                    if username.contains(':') {
+                        return Err(
+                            "diagnostics_endpoint.basic_username cannot contain ':'".to_string()
+                        );
+                    }
+                    if password.len() < 16 {
+                        return Err("diagnostics_endpoint.basic_password must contain at least 16 characters".to_string());
+                    }
+                }
+                _ => {
+                    return Err(
+                        "diagnostics_endpoint.auth must be one of: token, basic".to_string()
+                    );
+                }
+            }
+        }
+
         let storage_backend = self.effective_storage_backend();
         if !matches!(storage_backend.as_str(), "filesystem" | "s3") {
             return Err("storage.backend must be one of: filesystem, s3".to_string());
@@ -871,6 +1072,12 @@ impl AppConfig {
         {
             return Err("search timeout/worker settings must be greater than zero".to_string());
         }
+        if self.sync.interval_secs == 0 || self.sync.deep_index_batch_size == 0 {
+            return Err(
+                "sync.interval_secs and sync.deep_index_batch_size must be greater than zero"
+                    .to_string(),
+            );
+        }
         if self.cluster_mode && self.database_backend == "sqlite" {
             return Err(
                 "CLUSTER_MODE requires a shared mysql/pgsql application database; Redis only replaces session persistence"

src/db/folders.rs

@@ -12,6 +12,7 @@ pub struct CachedFolder {
     pub unread_count: u32,
     pub uid_validity: u32,
     pub highest_modseq: u64,
+    pub counter_generation: u64,
 }
 
 #[allow(clippy::too_many_arguments)]
@@ -68,6 +69,7 @@ pub fn get_all_folders(conn: &Connection) -> Result<Vec<CachedFolder>, String> {
         .query_map([], |row| {
             let is_subscribed_int: i32 = row.get(4)?;
             let highest_modseq_int: i64 = row.get(8)?;
+            let counter_generation_int: i64 = row.get(9)?;
             Ok(CachedFolder {
                 name: row.get(0)?,
                 delimiter: row.get(1)?,
@@ -78,6 +80,7 @@ pub fn get_all_folders(conn: &Connection) -> Result<Vec<CachedFolder>, String> {
                 unread_count: row.get(6)?,
                 uid_validity: row.get(7)?,
                 highest_modseq: highest_modseq_int as u64,
+                counter_generation: counter_generation_int as u64,
             })
         })
         .map_err(|e| format!("Failed to query folders: {e}"))?;
@@ -118,6 +121,7 @@ pub fn touch_all_folders(conn: &Connection) -> Result<(), String> {
     Ok(())
 }
 
+#[cfg(test)]
 pub fn update_folder_status(
     conn: &Connection,
     name: &str,
@@ -147,21 +151,6 @@ pub fn update_folder_sync_status(
     Ok(())
 }
 
-pub fn refresh_unread_count(conn: &Connection, folder_name: &str) -> Result<(), String> {
-    let unread: u32 = conn
-        .query_row(
-            crate::dbq!(db_folders::Q_008),
-            params![folder_name],
-            |row| row.get(0),
-        )
-        .map_err(|e| format!("Failed to count unread messages: {e}"))?;
-
-    conn.execute(crate::dbq!(db_folders::Q_009), params![unread, folder_name])
-        .map_err(|e| format!("Failed to update unread_count: {e}"))?;
-
-    Ok(())
-}
-
 pub fn set_unread_count(
     conn: &Connection,
     folder_name: &str,
@@ -175,15 +164,74 @@ pub fn set_unread_count(
     Ok(())
 }
 
-pub fn mark_folder_messages_fresh(conn: &Connection, folder_name: &str) -> Result<(), String> {
+pub fn set_folder_counts(
-    conn.execute(crate::dbq!(db_folders::Q_029), params![folder_name])
+    conn: &Connection,
-        .map_err(|e| format!("Failed to mark folder messages fresh: {e}"))?;
+    folder_name: &str,
+    total_count: u32,
+    unread_count: u32,
+) -> Result<(), String> {
+    conn.execute(
+        crate::dbq!(db_folders::Q_030),
+        params![total_count, unread_count, folder_name],
+    )
+    .map_err(|e| format!("Failed to set folder counts: {e}"))?;
     Ok(())
 }
 
-pub fn adjust_unread_count(conn: &Connection, folder_name: &str, delta: i32) -> Result<(), String> {
+pub fn update_folder_sync_cursor(
-    conn.execute(crate::dbq!(db_folders::Q_010), params![delta, folder_name])
+    conn: &Connection,
-        .map_err(|e| format!("Failed to adjust unread_count: {e}"))?;
+    folder_name: &str,
+    uid_validity: u32,
+    highest_modseq: u64,
+) -> Result<(), String> {
+    conn.execute(
+        crate::dbq!(db_folders::Q_031),
+        params![uid_validity, highest_modseq as i64, folder_name],
+    )
+    .map_err(|e| format!("Failed to update folder sync cursor: {e}"))?;
+    Ok(())
+}
+
+pub fn set_folder_counts_if_unchanged(
+    conn: &Connection,
+    folder_name: &str,
+    expected_generation: u64,
+    total_count: u32,
+    unread_count: u32,
+) -> Result<bool, String> {
+    let changed = conn
+        .execute(
+            crate::dbq!(db_folders::Q_032),
+            params![
+                total_count,
+                unread_count,
+                folder_name,
+                expected_generation as i64
+            ],
+        )
+        .map_err(|e| format!("Failed to conditionally set folder counts: {e}"))?;
+    Ok(changed > 0)
+}
+
+pub fn pending_message_sync_count(conn: &Connection) -> Result<u32, String> {
+    let mut pending = 0u64;
+    for folder in get_all_folders(conn)? {
+        if folder
+            .flags
+            .split(',')
+            .any(|flag| flag.trim().eq_ignore_ascii_case("\\Noselect"))
+        {
+            continue;
+        }
+        let cached = crate::db::messages::count_messages(conn, &folder.name)?;
+        pending = pending.saturating_add(folder.total_count.saturating_sub(cached) as u64);
+    }
+    Ok(pending.min(u32::MAX as u64) as u32)
+}
+
+pub fn mark_folder_messages_fresh(conn: &Connection, folder_name: &str) -> Result<(), String> {
+    conn.execute(crate::dbq!(db_folders::Q_029), params![folder_name])
+        .map_err(|e| format!("Failed to mark folder messages fresh: {e}"))?;
     Ok(())
 }
 
@@ -237,6 +285,7 @@ pub fn get_folder(conn: &Connection, name: &str) -> Result<Option<CachedFolder>,
     let result = conn.query_row(crate::dbq!(db_folders::Q_015), params![name], |row| {
         let is_subscribed_int: i32 = row.get(4)?;
         let highest_modseq_int: i64 = row.get(8)?;
+        let counter_generation_int: i64 = row.get(9)?;
         Ok(CachedFolder {
             name: row.get(0)?,
             delimiter: row.get(1)?,
@@ -247,6 +296,7 @@ pub fn get_folder(conn: &Connection, name: &str) -> Result<Option<CachedFolder>,
             unread_count: row.get(6)?,
             uid_validity: row.get(7)?,
             highest_modseq: highest_modseq_int as u64,
+            counter_generation: counter_generation_int as u64,
         })
     });
 
@@ -433,6 +483,59 @@ mod tests {
         assert!(!is_folder_fresh(&conn, "Sent", 30).unwrap());
     }
 
+    #[test]
+    fn conditional_folder_counts_reject_stale_writer() {
+        let conn = open_test_db();
+        upsert_folder(&conn, "INBOX", None, None, "", true, 3444, 12, 1, 50).unwrap();
+
+        let generation = get_folder(&conn, "INBOX")
+            .unwrap()
+            .unwrap()
+            .counter_generation;
+        assert!(set_folder_counts_if_unchanged(&conn, "INBOX", generation, 3444, 11).unwrap());
+        assert!(!set_folder_counts_if_unchanged(&conn, "INBOX", generation, 3444, 10).unwrap());
+
+        let folder = get_folder(&conn, "INBOX").unwrap().unwrap();
+        assert_eq!(folder.total_count, 3444);
+        assert_eq!(folder.unread_count, 11);
+    }
+
+    #[test]
+    fn counter_generation_blocks_aba_stale_writer() {
+        let conn = open_test_db();
+        upsert_folder(&conn, "INBOX", None, None, "", true, 3444, 12, 1, 50).unwrap();
+
+        let generation_12 = get_folder(&conn, "INBOX")
+            .unwrap()
+            .unwrap()
+            .counter_generation;
+        assert!(set_folder_counts_if_unchanged(&conn, "INBOX", generation_12, 3444, 11).unwrap());
+
+        let generation_11 = get_folder(&conn, "INBOX")
+            .unwrap()
+            .unwrap()
+            .counter_generation;
+        assert!(set_folder_counts_if_unchanged(&conn, "INBOX", generation_11, 3444, 12).unwrap());
+        assert!(!set_folder_counts_if_unchanged(&conn, "INBOX", generation_12, 3444, 10).unwrap());
+        let folder = get_folder(&conn, "INBOX").unwrap().unwrap();
+        assert_eq!((folder.total_count, folder.unread_count), (3444, 12));
+        assert!(folder.counter_generation > generation_12);
+    }
+
+    #[test]
+    fn sync_cursor_update_does_not_change_authoritative_counts() {
+        let conn = open_test_db();
+        upsert_folder(&conn, "INBOX", None, None, "", true, 3444, 12, 1, 50).unwrap();
+
+        update_folder_sync_cursor(&conn, "INBOX", 2, 75).unwrap();
+
+        let folder = get_folder(&conn, "INBOX").unwrap().unwrap();
+        assert_eq!(folder.total_count, 3444);
+        assert_eq!(folder.unread_count, 12);
+        assert_eq!(folder.uid_validity, 2);
+        assert_eq!(folder.highest_modseq, 75);
+    }
+
     #[test]
     fn test_remove_stale_folders() {
         let conn = open_test_db();

src/db/messages.rs

@@ -476,6 +476,11 @@ pub fn get_unindexed_messages(conn: &Connection, limit: u32) -> Result<Vec<(Stri
     Ok(result)
 }
 
+pub fn count_unindexed_messages(conn: &Connection) -> Result<u32, String> {
+    conn.query_row(crate::dbq!(db_messages::Q_015), [], |row| row.get(0))
+        .map_err(|e| format!("Failed to count unindexed messages: {e}"))
+}
+
 pub fn get_all_uids_and_flags(
     conn: &Connection,
     folder: &str,

src/db/pool.rs

@@ -7,6 +7,7 @@ use std::sync::{Arc, Mutex, OnceLock, mpsc};
 
 use rusqlite::OptionalExtension as _;
 use rusqlite::types::{ToSql, ToSqlOutput, Value};
+use serde::Serialize;
 use sha2::{Digest, Sha256};
 use sqlx::pool::PoolConnection;
 use sqlx::{Executor as _, MySql, MySqlPool, PgPool, Postgres, Row as SqlxRow};
@@ -20,18 +21,36 @@ const SQLITE_SCHEMA: &str = include_str!("../../migrations/sqlite/schema.sql");
 const MYSQL_SCHEMA: &str = include_str!("../../migrations/mysql/schema.sql");
 const PGSQL_SCHEMA: &str = include_str!("../../migrations/pgsql/schema.sql");
 
-const SQLITE_MIGRATIONS: &[(u32, &str)] = &[(
+const SQLITE_MIGRATIONS: &[(u32, &str)] = &[
-    47,
+    (
-    include_str!("../../migrations/sqlite/V047__blob_keys_and_search_outbox.sql"),
+        47,
-)];
+        include_str!("../../migrations/sqlite/V047__blob_keys_and_search_outbox.sql"),
-const MYSQL_MIGRATIONS: &[(u32, &str)] = &[(
+    ),
-    47,
+    (
-    include_str!("../../migrations/mysql/V047__blob_keys_and_search_outbox.sql"),
+        48,
-)];
+        include_str!("../../migrations/sqlite/V048__folder_counter_generation.sql"),
-const PGSQL_MIGRATIONS: &[(u32, &str)] = &[(
+    ),
-    47,
+];
-    include_str!("../../migrations/pgsql/V047__blob_keys_and_search_outbox.sql"),
+const MYSQL_MIGRATIONS: &[(u32, &str)] = &[
-)];
+    (
+        47,
+        include_str!("../../migrations/mysql/V047__blob_keys_and_search_outbox.sql"),
+    ),
+    (
+        48,
+        include_str!("../../migrations/mysql/V048__folder_counter_generation.sql"),
+    ),
+];
+const PGSQL_MIGRATIONS: &[(u32, &str)] = &[
+    (
+        47,
+        include_str!("../../migrations/pgsql/V047__blob_keys_and_search_outbox.sql"),
+    ),
+    (
+        48,
+        include_str!("../../migrations/pgsql/V048__folder_counter_generation.sql"),
+    ),
+];
 
 const TENANT_TABLES: &[&str] = &[
     "calendar_events",
@@ -93,6 +112,26 @@ const IMPORT_TABLES: &[&str] = &[
     "user_meta",
 ];
 
+#[derive(Debug, Clone, Serialize)]
+pub struct DatabaseDiagnostics {
+    pub backend: String,
+    pub status: String,
+    pub latency_ms: u128,
+    pub pool_size: Option<u32>,
+    pub idle_connections: Option<usize>,
+    pub database_bytes: Option<u64>,
+    pub engine_version: Option<String>,
+    pub account_count: Option<u64>,
+    pub schema_version_min: Option<u32>,
+    pub schema_version_max: Option<u32>,
+    pub schema_aligned: Option<bool>,
+    pub expected_schema_version: u32,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+type SqliteDiagnosticsProbe = (u64, Option<u32>, Option<u32>, Option<u64>, String);
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum DatabaseBackend {
     Sqlite,
@@ -312,6 +351,188 @@ pub fn configured_backend() -> DatabaseBackend {
     }
 }
 
+pub async fn diagnostics() -> DatabaseDiagnostics {
+    let started = std::time::Instant::now();
+    let expected = latest_schema_version();
+    match DATABASE.get() {
+        Some(ConfiguredDatabase::Sqlite { path }) => {
+            let path = path.clone();
+            let result = tokio::task::spawn_blocking(move || -> Result<SqliteDiagnosticsProbe, String> {
+                let conn = rusqlite::Connection::open(&path)
+                    .map_err(|e| format!("failed to open SQLite diagnostics connection: {e}"))?;
+                conn.query_row("SELECT 1", [], |_row| Ok(()))
+                    .map_err(|e| format!("SQLite probe failed: {e}"))?;
+                let engine_version: String = conn
+                    .query_row("SELECT sqlite_version()", [], |row| row.get(0))
+                    .map_err(|e| format!("SQLite version probe failed: {e}"))?;
+                let (count, min_version, max_version): (i64, Option<i64>, Option<i64>) = conn
+                    .query_row(
+                        "SELECT COUNT(*), MIN(schema_version), MAX(schema_version) FROM rustbox_accounts",
+                        [],
+                        |row| Ok((row.get(0)?, row.get(1)?, row.get(2)?)),
+                    )
+                    .map_err(|e| format!("SQLite account diagnostics failed: {e}"))?;
+                let bytes = std::fs::metadata(&path).ok().map(|meta| meta.len());
+                Ok((
+                    count.max(0) as u64,
+                    min_version.and_then(|value| u32::try_from(value).ok()),
+                    max_version.and_then(|value| u32::try_from(value).ok()),
+                    bytes,
+                    engine_version,
+                ))
+            }).await;
+            match result {
+                Ok(Ok((count, min_version, max_version, bytes, engine_version))) => {
+                    DatabaseDiagnostics {
+                        backend: "sqlite".to_string(),
+                        status: "ok".to_string(),
+                        latency_ms: started.elapsed().as_millis(),
+                        pool_size: None,
+                        idle_connections: None,
+                        database_bytes: bytes,
+                        engine_version: Some(engine_version),
+                        account_count: Some(count),
+                        schema_version_min: min_version,
+                        schema_version_max: max_version,
+                        schema_aligned: Some(
+                            count == 0
+                                || (min_version == Some(expected) && max_version == Some(expected)),
+                        ),
+                        expected_schema_version: expected,
+                        error: None,
+                    }
+                }
+                other => DatabaseDiagnostics {
+                    backend: "sqlite".to_string(),
+                    status: "error".to_string(),
+                    latency_ms: started.elapsed().as_millis(),
+                    pool_size: None,
+                    idle_connections: None,
+                    database_bytes: None,
+                    engine_version: None,
+                    account_count: None,
+                    schema_version_min: None,
+                    schema_version_max: None,
+                    schema_aligned: None,
+                    expected_schema_version: expected,
+                    error: Some(match other {
+                        Ok(Err(error)) => error,
+                        Err(error) => format!("SQLite diagnostics task failed: {error}"),
+                        Ok(Ok(_)) => unreachable!(),
+                    }),
+                },
+            }
+        }
+        Some(ConfiguredDatabase::Mysql { pool, .. }) => {
+            let result: Result<(i64, Option<i64>, Option<i64>, String), String> = async {
+                sqlx::query_scalar::<_, i32>("SELECT 1")
+                    .fetch_one(pool)
+                    .await
+                    .map_err(|e| format!("MySQL probe failed: {e}"))?;
+                let engine_version: String = sqlx::query_scalar("SELECT VERSION()")
+                    .fetch_one(pool)
+                    .await
+                    .map_err(|e| format!("MySQL version probe failed: {e}"))?;
+                let (count, min, max): (i64, Option<i64>, Option<i64>) = sqlx::query_as("SELECT COUNT(*), MIN(schema_version), MAX(schema_version) FROM rustbox_accounts")
+                    .fetch_one(pool)
+                    .await
+                    .map_err(|e| format!("MySQL account diagnostics failed: {e}"))?;
+                Ok((count, min, max, engine_version))
+            }.await;
+            let (status, account_count, min_version, max_version, engine_version, error) =
+                match result {
+                    Ok((count, min, max, version)) => (
+                        "ok",
+                        Some(count.max(0) as u64),
+                        min.and_then(|v| u32::try_from(v).ok()),
+                        max.and_then(|v| u32::try_from(v).ok()),
+                        Some(version),
+                        None,
+                    ),
+                    Err(error) => ("error", None, None, None, None, Some(error)),
+                };
+            DatabaseDiagnostics {
+                backend: "mysql".to_string(),
+                status: status.to_string(),
+                latency_ms: started.elapsed().as_millis(),
+                pool_size: Some(pool.size()),
+                idle_connections: Some(pool.num_idle()),
+                database_bytes: None,
+                engine_version,
+                account_count,
+                schema_version_min: min_version,
+                schema_version_max: max_version,
+                schema_aligned: account_count.map(|count| {
+                    count == 0 || (min_version == Some(expected) && max_version == Some(expected))
+                }),
+                expected_schema_version: expected,
+                error,
+            }
+        }
+        Some(ConfiguredDatabase::Pgsql { pool, .. }) => {
+            let result: Result<(i64, Option<i64>, Option<i64>, String), String> = async {
+                sqlx::query_scalar::<_, i32>("SELECT 1")
+                    .fetch_one(pool)
+                    .await
+                    .map_err(|e| format!("PostgreSQL probe failed: {e}"))?;
+                let engine_version: String = sqlx::query_scalar("SHOW server_version")
+                    .fetch_one(pool)
+                    .await
+                    .map_err(|e| format!("PostgreSQL version probe failed: {e}"))?;
+                let (count, min, max): (i64, Option<i64>, Option<i64>) = sqlx::query_as("SELECT COUNT(*), MIN(schema_version), MAX(schema_version) FROM rustbox_accounts")
+                    .fetch_one(pool)
+                    .await
+                    .map_err(|e| format!("PostgreSQL account diagnostics failed: {e}"))?;
+                Ok((count, min, max, engine_version))
+            }.await;
+            let (status, account_count, min_version, max_version, engine_version, error) =
+                match result {
+                    Ok((count, min, max, version)) => (
+                        "ok",
+                        Some(count.max(0) as u64),
+                        min.and_then(|v| u32::try_from(v).ok()),
+                        max.and_then(|v| u32::try_from(v).ok()),
+                        Some(version),
+                        None,
+                    ),
+                    Err(error) => ("error", None, None, None, None, Some(error)),
+                };
+            DatabaseDiagnostics {
+                backend: "pgsql".to_string(),
+                status: status.to_string(),
+                latency_ms: started.elapsed().as_millis(),
+                pool_size: Some(pool.size()),
+                idle_connections: Some(pool.num_idle()),
+                database_bytes: None,
+                engine_version,
+                account_count,
+                schema_version_min: min_version,
+                schema_version_max: max_version,
+                schema_aligned: account_count.map(|count| {
+                    count == 0 || (min_version == Some(expected) && max_version == Some(expected))
+                }),
+                expected_schema_version: expected,
+                error,
+            }
+        }
+        None => DatabaseDiagnostics {
+            backend: "unconfigured".to_string(),
+            status: "error".to_string(),
+            latency_ms: started.elapsed().as_millis(),
+            pool_size: None,
+            idle_connections: None,
+            database_bytes: None,
+            engine_version: None,
+            account_count: None,
+            schema_version_min: None,
+            schema_version_max: None,
+            schema_aligned: None,
+            expected_schema_version: expected,
+            error: Some("database is not configured".to_string()),
+        },
+    }
+}
+
 pub fn list_account_user_hashes() -> Result<Vec<String>, String> {
     match DATABASE.get() {
         Some(ConfiguredDatabase::Sqlite { path }) => {
@@ -1838,7 +2059,7 @@ fn tenant_prefix(user_hash: &str) -> Result<String, String> {
     Ok(format!("u_{}__", &normalized[..24]))
 }
 
-fn latest_schema_version() -> u32 {
+pub fn latest_schema_version() -> u32 {
     let migrations = match configured_backend() {
         DatabaseBackend::Sqlite => SQLITE_MIGRATIONS,
         DatabaseBackend::Mysql => MYSQL_MIGRATIONS,
@@ -2108,8 +2329,6 @@ fn ensure_server_tenant(
             let tenant = tenant_schema(PGSQL_SCHEMA, &prefix)?;
             let legacy_path = legacy_path.clone();
             runtime_wait(runtime, async move {
-                // PostgreSQL advisory locks are session-scoped, so they work across all RustBox nodes
-                // that share this database and disappear automatically with the connection.
                 let lock_name = format!("rustbox:{prefix}");
                 let mut lock_conn = pool.acquire().await.map_err(|e| {
                     format!("failed to acquire PostgreSQL provisioning connection: {e}")

src/imap/client.rs

@@ -19,6 +19,60 @@ pub(crate) use super::connection::connect;
 #[path = "mock.rs"]
 pub mod mock;
 
+async fn folder_status_extended_on_session(
+    session: &mut async_imap::Session<super::connection::ImapStream>,
+    folder: &str,
+) -> Result<FolderStatusExtended, ImapError> {
+    if let Ok(mailbox) = session
+        .status(
+            folder,
+            "(MESSAGES UIDNEXT UIDVALIDITY UNSEEN HIGHESTMODSEQ)",
+        )
+        .await
+        && let Some(unseen) = mailbox.unseen
+    {
+        return Ok(FolderStatusExtended {
+            uid_validity: mailbox.uid_validity.unwrap_or(0),
+            exists: mailbox.exists,
+            uid_next: mailbox.uid_next.unwrap_or(0),
+            unseen,
+            highest_modseq: mailbox.highest_modseq.unwrap_or(0),
+        });
+    }
+
+    if let Ok(mailbox) = session
+        .status(folder, "(MESSAGES UIDNEXT UIDVALIDITY UNSEEN)")
+        .await
+        && let Some(unseen) = mailbox.unseen
+    {
+        return Ok(FolderStatusExtended {
+            uid_validity: mailbox.uid_validity.unwrap_or(0),
+            exists: mailbox.exists,
+            uid_next: mailbox.uid_next.unwrap_or(0),
+            unseen,
+            highest_modseq: mailbox.highest_modseq.unwrap_or(0),
+        });
+    }
+
+    let mailbox = match session.select_condstore(folder).await {
+        Ok(mailbox) => mailbox,
+        Err(_) => session.select(folder).await.map_err(map_imap_error)?,
+    };
+    let unseen = session
+        .uid_search("UNSEEN")
+        .await
+        .map_err(map_imap_error)?
+        .len() as u32;
+
+    Ok(FolderStatusExtended {
+        uid_validity: mailbox.uid_validity.unwrap_or(0),
+        exists: mailbox.exists,
+        uid_next: mailbox.uid_next.unwrap_or(0),
+        unseen,
+        highest_modseq: mailbox.highest_modseq.unwrap_or(0),
+    })
+}
+
 #[allow(dead_code)]
 #[allow(clippy::double_must_use)]
 #[async_trait]
@@ -170,6 +224,21 @@ pub trait ImapClient: Send + Sync {
         folder: &str,
     ) -> Result<FolderStatusExtended, ImapError>;
 
+    async fn folder_statuses_extended(
+        &self,
+        creds: &ImapCredentials,
+        folders: &[String],
+    ) -> Result<Vec<(String, FolderStatusExtended)>, ImapError> {
+        let mut statuses = Vec::with_capacity(folders.len());
+        for folder in folders {
+            statuses.push((
+                folder.clone(),
+                self.folder_status_extended(creds, folder).await?,
+            ));
+        }
+        Ok(statuses)
+    }
+
     async fn fetch_changed_flags(
         &self,
         creds: &ImapCredentials,
@@ -1073,25 +1142,32 @@ impl ImapClient for RealImapClient {
         folder: &str,
     ) -> Result<FolderStatusExtended, ImapError> {
         let mut session = self.pool.checkout(creds).await?;
+        let result = folder_status_extended_on_session(&mut session, folder).await;
+        if result.is_ok() {
+            session.recycle();
+        }
+        result
+    }
 
-        let mailbox = session
+    async fn folder_statuses_extended(
-            .status(
+        &self,
-                folder,
+        creds: &ImapCredentials,
-                "(MESSAGES UIDNEXT UIDVALIDITY UNSEEN HIGHESTMODSEQ)",
+        folders: &[String],
-            )
+    ) -> Result<Vec<(String, FolderStatusExtended)>, ImapError> {
-            .await
+        let mut session = self.pool.checkout(creds).await?;
-            .map_err(map_imap_error)?;
+        let mut statuses = Vec::with_capacity(folders.len());
 
-        let result = FolderStatusExtended {
+        for folder in folders {
-            uid_validity: mailbox.uid_validity.unwrap_or(0),
+            match folder_status_extended_on_session(&mut session, folder).await {
-            exists: mailbox.exists,
+                Ok(status) => statuses.push((folder.clone(), status)),
-            uid_next: mailbox.uid_next.unwrap_or(0),
+                Err(error) => {
-            unseen: mailbox.unseen.unwrap_or(0),
+                    tracing::debug!(folder = %folder, error = %error, "Skipping folder STATUS refresh");
-            highest_modseq: mailbox.highest_modseq.unwrap_or(0),
+                }
-        };
+            }
+        }
 
         session.recycle();
-        Ok(result)
+        Ok(statuses)
     }
 
     async fn fetch_changed_flags(

src/main.rs

@@ -186,9 +186,22 @@ async fn run_search_reindex(
     Ok(())
 }
 
+fn default_log_filter(log_level: &str) -> String {
+    let app_level = log_level.trim().to_ascii_lowercase();
+    match app_level.as_str() {
+        "trace" => "warn,rustbox=trace,tower_http=debug".to_string(),
+        "debug" => "warn,rustbox=debug,tower_http=info".to_string(),
+        "info" => "warn,rustbox=info,tower_http=info".to_string(),
+        "warn" => "warn,rustbox=warn,tower_http=warn".to_string(),
+        "error" => "error,rustbox=error,tower_http=error".to_string(),
+        "off" => "off".to_string(),
+        _ => "warn,rustbox=info,tower_http=info".to_string(),
+    }
+}
+
 fn init_tracing(log_dir: Option<&str>, log_level: &str) -> Result<(), Box<dyn std::error::Error>> {
     let env_filter = EnvFilter::try_from_default_env()
-        .unwrap_or_else(|_| EnvFilter::new(log_level.trim().to_ascii_lowercase()));
+        .unwrap_or_else(|_| EnvFilter::new(default_log_filter(log_level)));
     if let Some(log_dir) = log_dir.map(str::trim).filter(|value| !value.is_empty()) {
         std::fs::create_dir_all(log_dir)?;
         let log_path = std::path::Path::new(log_dir).join("rustbox.log");

src/queries/mysql/queries.rs

@@ -187,24 +187,25 @@ pub mod db_folders {
          ON DUPLICATE KEY UPDATE
              delimiter=VALUES(delimiter), parent=VALUES(parent), flags=VALUES(flags),
              is_subscribed=VALUES(is_subscribed), total_count=VALUES(total_count), unread_count=VALUES(unread_count),
-             uid_validity=VALUES(uid_validity), highest_modseq=VALUES(highest_modseq), updated_at=CURRENT_TIMESTAMP";
+             uid_validity=VALUES(uid_validity), highest_modseq=VALUES(highest_modseq),
+             counter_generation=counter_generation + 1, updated_at=CURRENT_TIMESTAMP";
     pub const Q_002: &str = "INSERT IGNORE INTO folders
             (name, delimiter, flags, is_subscribed, updated_at)
          VALUES (?, ?, ?, 1, CURRENT_TIMESTAMP)";
     pub const Q_003: &str = "SELECT name, delimiter, parent, flags, is_subscribed,
-                    total_count, unread_count, uid_validity, highest_modseq
+                    total_count, unread_count, uid_validity, highest_modseq, counter_generation
              FROM folders
              ORDER BY name";
     pub const Q_004: &str = "DELETE FROM folders";
     pub const Q_005: &str = "UPDATE folders SET updated_at = CURRENT_TIMESTAMP";
-    pub const Q_006: &str = "UPDATE folders SET uid_validity = ?, total_count = ?, messages_updated_at = CURRENT_TIMESTAMP
+    pub const Q_006: &str = "UPDATE folders SET uid_validity = ?, total_count = ?, counter_generation = counter_generation + 1, messages_updated_at = CURRENT_TIMESTAMP
          WHERE name = ?";
     pub const Q_007: &str =
-        "UPDATE folders SET uid_validity = ?, total_count = ?, highest_modseq = ?
+        "UPDATE folders SET uid_validity = ?, total_count = ?, highest_modseq = ?, counter_generation = counter_generation + 1
          WHERE name = ?";
     pub const Q_008: &str = "SELECT CAST(COUNT(*) AS SIGNED) FROM messages WHERE folder = ? AND LOCATE(CONCAT(CHAR(92), 'Seen'), flags) = 0";
-    pub const Q_009: &str = "UPDATE folders SET unread_count = ? WHERE name = ?";
+    pub const Q_009: &str = "UPDATE folders SET unread_count = ?, counter_generation = counter_generation + 1 WHERE name = ?";
-    pub const Q_010: &str = "UPDATE folders SET unread_count = GREATEST(0, CAST(unread_count AS SIGNED) + ?) WHERE name = ?";
+    pub const Q_010: &str = "UPDATE folders SET unread_count = GREATEST(0, CAST(unread_count AS SIGNED) + ?), counter_generation = counter_generation + 1 WHERE name = ?";
     pub const Q_011: &str = "SELECT EXISTS(
                 SELECT 1 FROM folders
                 WHERE updated_at > DATE_FORMAT(DATE_SUB(CURRENT_TIMESTAMP, INTERVAL ? SECOND), '%Y-%m-%d %H:%i:%s')
@@ -216,14 +217,14 @@ pub mod db_folders {
     pub const Q_013: &str = "SELECT messages_updated_at IS NULL FROM folders WHERE name = ?";
     pub const Q_014: &str = "UPDATE folders SET messages_updated_at = NULL WHERE name = ?";
     pub const Q_015: &str = "SELECT name, delimiter, parent, flags, is_subscribed,
-                total_count, unread_count, uid_validity, highest_modseq
+                total_count, unread_count, uid_validity, highest_modseq, counter_generation
          FROM folders
          WHERE name = ?";
     pub const Q_016: &str = "DELETE FROM messages WHERE folder = ?";
     pub const Q_017: &str = "DELETE FROM folders WHERE name = ?";
     pub const Q_018: &str = "SELECT 1";
-    pub const Q_019: &str = "INSERT INTO folders (name, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, updated_at, messages_updated_at)
+    pub const Q_019: &str = "INSERT INTO folders (name, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, counter_generation, updated_at, messages_updated_at)
-         SELECT ?, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, CURRENT_TIMESTAMP, messages_updated_at
+         SELECT ?, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, counter_generation, CURRENT_TIMESTAMP, messages_updated_at
          FROM folders WHERE name = ?";
     pub const Q_020: &str = "UPDATE messages SET folder = ? WHERE folder = ?";
     pub const Q_021: &str = "UPDATE message_tags SET message_folder = ? WHERE message_folder = ?";
@@ -235,9 +236,13 @@ pub mod db_folders {
     pub const Q_026: &str =
         "UPDATE folders SET messages_updated_at = '2000-01-01 00:00:00' WHERE name = 'Sent'";
     pub const Q_027: &str = "SELECT messages_updated_at FROM folders WHERE name = 'Sent'";
-    pub const Q_028: &str = "UPDATE folders SET unread_count = ? WHERE name = ?";
+    pub const Q_028: &str = "UPDATE folders SET unread_count = ?, counter_generation = counter_generation + 1 WHERE name = ?";
     pub const Q_029: &str =
         "UPDATE folders SET messages_updated_at = CURRENT_TIMESTAMP WHERE name = ?";
+    pub const Q_030: &str = "UPDATE folders SET total_count = ?, unread_count = ?, counter_generation = counter_generation + 1 WHERE name = ?";
+    pub const Q_031: &str =
+        "UPDATE folders SET uid_validity = ?, highest_modseq = ? WHERE name = ?";
+    pub const Q_032: &str = "UPDATE folders SET total_count = ?, unread_count = ?, counter_generation = counter_generation + 1 WHERE name = ? AND counter_generation = ?";
     pub const FORMAT_001: &str = "DELETE FROM folders WHERE name NOT IN ({})";
 }
 
@@ -310,6 +315,12 @@ pub mod db_messages {
              LIMIT ?";
     pub const Q_013: &str = "SELECT uid, flags FROM messages WHERE folder = ?";
     pub const Q_014: &str = "SELECT CAST(SUM(size) AS SIGNED) FROM messages";
+    pub const Q_015: &str = "SELECT COUNT(*) FROM messages
+             WHERE body_cached = 0
+               AND lower(folder) NOT IN ('trash', 'junk', 'spam')
+               AND lower(folder) NOT LIKE '%/trash'
+               AND lower(folder) NOT LIKE '%/junk'
+               AND lower(folder) NOT LIKE '%/spam'";
     pub const FORMAT_001: &str = "SELECT {MSG_SELECT_COLS}
          FROM messages
          WHERE folder = ?
@@ -463,9 +474,9 @@ pub mod routes_diagnostics {
 
 pub mod routes_folder_mgmt {
     pub const Q_001: &str = "UPDATE messages SET flags = CASE WHEN flags = '' THEN ?2 ELSE CONCAT(flags, ',', ?2) END WHERE folder = ?1 AND LOCATE(?2, flags) = 0";
-    pub const Q_002: &str = "UPDATE folders SET unread_count = 0 WHERE name = ?";
+    pub const Q_002: &str = "UPDATE folders SET unread_count = 0, counter_generation = counter_generation + 1 WHERE name = ?";
     pub const Q_003: &str = "SELECT uid FROM messages WHERE folder = ?";
-    pub const Q_004: &str = "UPDATE folders SET total_count = 0, unread_count = 0, messages_updated_at = CURRENT_TIMESTAMP WHERE name = ?";
+    pub const Q_004: &str = "UPDATE folders SET total_count = 0, unread_count = 0, counter_generation = counter_generation + 1, messages_updated_at = CURRENT_TIMESTAMP WHERE name = ?";
 }
 
 pub mod routes_messages_mod {

src/queries/pgsql/queries.rs

@@ -187,25 +187,26 @@ pub mod db_folders {
          VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, CURRENT_TIMESTAMP::text)
          ON CONFLICT (name) DO UPDATE SET delimiter=excluded.delimiter, parent=excluded.parent, flags=excluded.flags,
              is_subscribed=excluded.is_subscribed, total_count=excluded.total_count, unread_count=excluded.unread_count,
-             uid_validity=excluded.uid_validity, highest_modseq=excluded.highest_modseq, updated_at=CURRENT_TIMESTAMP::text";
+             uid_validity=excluded.uid_validity, highest_modseq=excluded.highest_modseq,
+             counter_generation=folders.counter_generation + 1, updated_at=CURRENT_TIMESTAMP::text";
     pub const Q_002: &str = "INSERT INTO folders
             (name, delimiter, flags, is_subscribed, updated_at)
          VALUES ($1, $2, $3, 1, CURRENT_TIMESTAMP::text) ON CONFLICT (name) DO NOTHING";
     pub const Q_003: &str = "SELECT name, delimiter, parent, flags, is_subscribed,
-                    total_count, unread_count, uid_validity, highest_modseq
+                    total_count, unread_count, uid_validity, highest_modseq, counter_generation
              FROM folders
              ORDER BY name";
     pub const Q_004: &str = "DELETE FROM folders";
     pub const Q_005: &str = "UPDATE folders SET updated_at = CURRENT_TIMESTAMP::text";
-    pub const Q_006: &str = "UPDATE folders SET uid_validity = $1, total_count = $2, messages_updated_at = CURRENT_TIMESTAMP::text
+    pub const Q_006: &str = "UPDATE folders SET uid_validity = $1, total_count = $2, counter_generation = counter_generation + 1, messages_updated_at = CURRENT_TIMESTAMP::text
          WHERE name = $3";
     pub const Q_007: &str =
-        "UPDATE folders SET uid_validity = $1, total_count = $2, highest_modseq = $3
+        "UPDATE folders SET uid_validity = $1, total_count = $2, highest_modseq = $3, counter_generation = counter_generation + 1
          WHERE name = $4";
     pub const Q_008: &str =
         "SELECT COUNT(*) FROM messages WHERE folder = $1 AND strpos(flags, chr(92) || 'Seen') = 0";
-    pub const Q_009: &str = "UPDATE folders SET unread_count = $1 WHERE name = $2";
+    pub const Q_009: &str = "UPDATE folders SET unread_count = $1, counter_generation = counter_generation + 1 WHERE name = $2";
-    pub const Q_010: &str = "UPDATE folders SET unread_count = GREATEST(0, CAST(unread_count AS INTEGER) + $1) WHERE name = $2";
+    pub const Q_010: &str = "UPDATE folders SET unread_count = GREATEST(0, CAST(unread_count AS INTEGER) + $1), counter_generation = counter_generation + 1 WHERE name = $2";
     pub const Q_011: &str = "SELECT EXISTS(
                 SELECT 1 FROM folders
                 WHERE updated_at > to_char(CURRENT_TIMESTAMP - ($1 * INTERVAL '1 second'), 'YYYY-MM-DD HH24:MI:SS')
@@ -217,14 +218,14 @@ pub mod db_folders {
     pub const Q_013: &str = "SELECT messages_updated_at IS NULL FROM folders WHERE name = $1";
     pub const Q_014: &str = "UPDATE folders SET messages_updated_at = NULL WHERE name = $1";
     pub const Q_015: &str = "SELECT name, delimiter, parent, flags, is_subscribed,
-                total_count, unread_count, uid_validity, highest_modseq
+                total_count, unread_count, uid_validity, highest_modseq, counter_generation
          FROM folders
          WHERE name = $1";
     pub const Q_016: &str = "DELETE FROM messages WHERE folder = $1";
     pub const Q_017: &str = "DELETE FROM folders WHERE name = $1";
     pub const Q_018: &str = "SELECT 1";
-    pub const Q_019: &str = "INSERT INTO folders (name, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, updated_at, messages_updated_at)
+    pub const Q_019: &str = "INSERT INTO folders (name, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, counter_generation, updated_at, messages_updated_at)
-         SELECT $1, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, CURRENT_TIMESTAMP::text, messages_updated_at
+         SELECT $1, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, counter_generation, CURRENT_TIMESTAMP::text, messages_updated_at
          FROM folders WHERE name = $2";
     pub const Q_020: &str = "UPDATE messages SET folder = $1 WHERE folder = $2";
     pub const Q_021: &str = "UPDATE message_tags SET message_folder = $1 WHERE message_folder = $2";
@@ -236,9 +237,13 @@ pub mod db_folders {
     pub const Q_026: &str =
         "UPDATE folders SET messages_updated_at = '2000-01-01 00:00:00' WHERE name = 'Sent'";
     pub const Q_027: &str = "SELECT messages_updated_at FROM folders WHERE name = 'Sent'";
-    pub const Q_028: &str = "UPDATE folders SET unread_count = $1 WHERE name = $2";
+    pub const Q_028: &str = "UPDATE folders SET unread_count = $1, counter_generation = counter_generation + 1 WHERE name = $2";
     pub const Q_029: &str =
         "UPDATE folders SET messages_updated_at = CURRENT_TIMESTAMP::text WHERE name = $1";
+    pub const Q_030: &str = "UPDATE folders SET total_count = $1, unread_count = $2, counter_generation = counter_generation + 1 WHERE name = $3";
+    pub const Q_031: &str =
+        "UPDATE folders SET uid_validity = $1, highest_modseq = $2 WHERE name = $3";
+    pub const Q_032: &str = "UPDATE folders SET total_count = $1, unread_count = $2, counter_generation = counter_generation + 1 WHERE name = $3 AND counter_generation = $4";
     pub const FORMAT_001: &str = "DELETE FROM folders WHERE name NOT IN ({})";
 }
 
@@ -310,6 +315,12 @@ pub mod db_messages {
              LIMIT $1";
     pub const Q_013: &str = "SELECT uid, flags FROM messages WHERE folder = $1";
     pub const Q_014: &str = "SELECT SUM(size)::bigint FROM messages";
+    pub const Q_015: &str = "SELECT COUNT(*) FROM messages
+             WHERE body_cached = 0
+               AND lower(folder) NOT IN ('trash', 'junk', 'spam')
+               AND lower(folder) NOT LIKE '%/trash'
+               AND lower(folder) NOT LIKE '%/junk'
+               AND lower(folder) NOT LIKE '%/spam'";
     pub const FORMAT_001: &str = "SELECT {MSG_SELECT_COLS}
          FROM messages
          WHERE folder = $1
@@ -467,9 +478,9 @@ pub mod routes_diagnostics {
 
 pub mod routes_folder_mgmt {
     pub const Q_001: &str = "UPDATE messages SET flags = CASE WHEN flags = '' THEN $2 ELSE flags || ',' || $2 END WHERE folder = $1 AND POSITION($2 IN flags) = 0";
-    pub const Q_002: &str = "UPDATE folders SET unread_count = 0 WHERE name = $1";
+    pub const Q_002: &str = "UPDATE folders SET unread_count = 0, counter_generation = counter_generation + 1 WHERE name = $1";
     pub const Q_003: &str = "SELECT uid FROM messages WHERE folder = $1";
-    pub const Q_004: &str = "UPDATE folders SET total_count = 0, unread_count = 0, messages_updated_at = CURRENT_TIMESTAMP::text WHERE name = $1";
+    pub const Q_004: &str = "UPDATE folders SET total_count = 0, unread_count = 0, counter_generation = counter_generation + 1, messages_updated_at = CURRENT_TIMESTAMP::text WHERE name = $1";
 }
 
 pub mod routes_messages_mod {

src/queries/sqlite/queries.rs

@@ -178,28 +178,33 @@ pub mod db_folder_preferences {
 }
 
 pub mod db_folders {
-    pub const Q_001: &str = "INSERT OR REPLACE INTO folders
+    pub const Q_001: &str = "INSERT INTO folders
             (name, delimiter, parent, flags, is_subscribed,
              total_count, unread_count, uid_validity, highest_modseq, updated_at)
-         VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, datetime('now'))";
+         VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, datetime('now'))
+         ON CONFLICT(name) DO UPDATE SET
+             delimiter=excluded.delimiter, parent=excluded.parent, flags=excluded.flags,
+             is_subscribed=excluded.is_subscribed, total_count=excluded.total_count, unread_count=excluded.unread_count,
+             uid_validity=excluded.uid_validity, highest_modseq=excluded.highest_modseq,
+             counter_generation=folders.counter_generation + 1, updated_at=datetime('now')";
     pub const Q_002: &str = "INSERT OR IGNORE INTO folders
             (name, delimiter, flags, is_subscribed, updated_at)
          VALUES (?1, ?2, ?3, 1, datetime('now'))";
     pub const Q_003: &str = "SELECT name, delimiter, parent, flags, is_subscribed,
-                    total_count, unread_count, uid_validity, highest_modseq
+                    total_count, unread_count, uid_validity, highest_modseq, counter_generation
              FROM folders
              ORDER BY name";
     pub const Q_004: &str = "DELETE FROM folders";
     pub const Q_005: &str = "UPDATE folders SET updated_at = datetime('now')";
-    pub const Q_006: &str = "UPDATE folders SET uid_validity = ?1, total_count = ?2, messages_updated_at = datetime('now')
+    pub const Q_006: &str = "UPDATE folders SET uid_validity = ?1, total_count = ?2, counter_generation = counter_generation + 1, messages_updated_at = datetime('now')
          WHERE name = ?3";
     pub const Q_007: &str =
-        "UPDATE folders SET uid_validity = ?1, total_count = ?2, highest_modseq = ?3
+        "UPDATE folders SET uid_validity = ?1, total_count = ?2, highest_modseq = ?3, counter_generation = counter_generation + 1
          WHERE name = ?4";
     pub const Q_008: &str =
         "SELECT COUNT(*) FROM messages WHERE folder = ?1 AND flags NOT LIKE '%\\Seen%'";
-    pub const Q_009: &str = "UPDATE folders SET unread_count = ?1 WHERE name = ?2";
+    pub const Q_009: &str = "UPDATE folders SET unread_count = ?1, counter_generation = counter_generation + 1 WHERE name = ?2";
-    pub const Q_010: &str = "UPDATE folders SET unread_count = MAX(0, CAST(unread_count AS INTEGER) + ?1) WHERE name = ?2";
+    pub const Q_010: &str = "UPDATE folders SET unread_count = MAX(0, CAST(unread_count AS INTEGER) + ?1), counter_generation = counter_generation + 1 WHERE name = ?2";
     pub const Q_011: &str = "SELECT EXISTS(
                 SELECT 1 FROM folders
                 WHERE updated_at > datetime('now', printf('-%d seconds', ?1))
@@ -211,14 +216,14 @@ pub mod db_folders {
     pub const Q_013: &str = "SELECT messages_updated_at IS NULL FROM folders WHERE name = ?1";
     pub const Q_014: &str = "UPDATE folders SET messages_updated_at = NULL WHERE name = ?1";
     pub const Q_015: &str = "SELECT name, delimiter, parent, flags, is_subscribed,
-                total_count, unread_count, uid_validity, highest_modseq
+                total_count, unread_count, uid_validity, highest_modseq, counter_generation
          FROM folders
          WHERE name = ?1";
     pub const Q_016: &str = "DELETE FROM messages WHERE folder = ?1";
     pub const Q_017: &str = "DELETE FROM folders WHERE name = ?1";
     pub const Q_018: &str = "PRAGMA defer_foreign_keys = ON;";
-    pub const Q_019: &str = "INSERT INTO folders (name, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, updated_at, messages_updated_at)
+    pub const Q_019: &str = "INSERT INTO folders (name, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, counter_generation, updated_at, messages_updated_at)
-         SELECT ?1, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, datetime('now'), messages_updated_at
+         SELECT ?1, delimiter, parent, flags, is_subscribed, total_count, unread_count, uid_validity, highest_modseq, counter_generation, datetime('now'), messages_updated_at
          FROM folders WHERE name = ?2";
     pub const Q_020: &str = "UPDATE messages SET folder = ?1 WHERE folder = ?2";
     pub const Q_021: &str = "UPDATE message_tags SET message_folder = ?1 WHERE message_folder = ?2";
@@ -230,9 +235,13 @@ pub mod db_folders {
     pub const Q_026: &str =
         "UPDATE folders SET messages_updated_at = '2000-01-01 00:00:00' WHERE name = 'Sent'";
     pub const Q_027: &str = "SELECT messages_updated_at FROM folders WHERE name = 'Sent'";
-    pub const Q_028: &str = "UPDATE folders SET unread_count = ?1 WHERE name = ?2";
+    pub const Q_028: &str = "UPDATE folders SET unread_count = ?1, counter_generation = counter_generation + 1 WHERE name = ?2";
     pub const Q_029: &str =
         "UPDATE folders SET messages_updated_at = datetime('now') WHERE name = ?1";
+    pub const Q_030: &str = "UPDATE folders SET total_count = ?1, unread_count = ?2, counter_generation = counter_generation + 1 WHERE name = ?3";
+    pub const Q_031: &str =
+        "UPDATE folders SET uid_validity = ?1, highest_modseq = ?2 WHERE name = ?3";
+    pub const Q_032: &str = "UPDATE folders SET total_count = ?1, unread_count = ?2, counter_generation = counter_generation + 1 WHERE name = ?3 AND counter_generation = ?4";
     pub const FORMAT_001: &str = "DELETE FROM folders WHERE name NOT IN ({})";
 }
 
@@ -299,6 +308,12 @@ pub mod db_messages {
              LIMIT ?1";
     pub const Q_013: &str = "SELECT uid, flags FROM messages WHERE folder = ?1";
     pub const Q_014: &str = "SELECT SUM(size) FROM messages";
+    pub const Q_015: &str = "SELECT COUNT(*) FROM messages
+             WHERE body_cached = 0
+               AND lower(folder) NOT IN ('trash', 'junk', 'spam')
+               AND lower(folder) NOT LIKE '%/trash'
+               AND lower(folder) NOT LIKE '%/junk'
+               AND lower(folder) NOT LIKE '%/spam'";
     pub const FORMAT_001: &str = "SELECT {MSG_SELECT_COLS}
          FROM messages
          WHERE folder = ?1
@@ -457,9 +472,9 @@ pub mod routes_diagnostics {
 
 pub mod routes_folder_mgmt {
     pub const Q_001: &str = "UPDATE messages SET flags = CASE WHEN flags = '' THEN ?2 ELSE flags || ',' || ?2 END WHERE folder = ?1 AND instr(flags, ?2) = 0";
-    pub const Q_002: &str = "UPDATE folders SET unread_count = 0 WHERE name = ?1";
+    pub const Q_002: &str = "UPDATE folders SET unread_count = 0, counter_generation = counter_generation + 1 WHERE name = ?1";
     pub const Q_003: &str = "SELECT uid FROM messages WHERE folder = ?1";
-    pub const Q_004: &str = "UPDATE folders SET total_count = 0, unread_count = 0, messages_updated_at = datetime('now') WHERE name = ?1";
+    pub const Q_004: &str = "UPDATE folders SET total_count = 0, unread_count = 0, counter_generation = counter_generation + 1, messages_updated_at = datetime('now') WHERE name = ?1";
 }
 
 pub mod routes_messages_mod {

src/realtime/events.rs

@@ -3,6 +3,12 @@ use std::collections::HashMap;
 use serde::Serialize;
 use tokio::sync::{RwLock, broadcast};
 
+#[derive(Debug, Clone, Serialize)]
+pub struct MessageFlagChange {
+    pub uid: u32,
+    pub flags: Vec<String>,
+}
+
 #[derive(Debug, Clone, Serialize)]
 #[serde(tag = "type", content = "data")]
 #[allow(dead_code)]
@@ -17,10 +23,32 @@ pub enum MailEvent {
 
     FlagsChanged {
         folder: String,
+        changes: Vec<MessageFlagChange>,
+    },
+
+    FolderAllRead {
+        folder: String,
+        through_uid: Option<u32>,
+    },
+
+    FolderStatus {
+        folder: String,
+        total_count: u32,
+        unread_count: u32,
     },
 
     FolderUpdated,
 
+    SyncStatus {
+        active: bool,
+        folder: Option<String>,
+        pending: u32,
+    },
+
+    SyncInventory {
+        pending: u32,
+    },
+
     IndexingStatus {
         active: bool,
         pending: u32,

src/realtime/idle.rs

@@ -2,16 +2,25 @@ use std::sync::Arc;
 
 use dashmap::DashMap;
 use futures::StreamExt;
+use serde::Serialize;
 use tokio::task::JoinHandle;
 
 use crate::config::AppConfig;
 use crate::imap::client::ImapCredentials;
 use crate::imap::connection::ImapStream;
 use crate::imap::parse::{decode_rfc2047, flag_to_string, has_attachments, imap_address_to_email};
-use crate::realtime::events::{EventBus, MailEvent};
+use crate::realtime::events::{EventBus, MailEvent, MessageFlagChange};
-use crate::search::engine::SearchEngine;
+use crate::search::engine::{IndexableMessage, SearchEngine, UserIndex};
 use crate::{db, imap};
 
+#[derive(Debug, Clone, Serialize)]
+pub struct IdleTaskDiagnostics {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub user_hash: Option<String>,
+    pub folder: String,
+    pub subscribers: usize,
+}
+
 pub struct IdleManager {
     tasks: DashMap<(String, String), IdleTask>,
 }
@@ -90,6 +99,21 @@ impl IdleManager {
     pub fn subscriber_count(&self) -> usize {
         self.tasks.iter().map(|task| task.value().subscribers).sum()
     }
+
+    pub fn diagnostics_snapshot(&self, include_user_identifiers: bool) -> Vec<IdleTaskDiagnostics> {
+        let mut tasks = self
+            .tasks
+            .iter()
+            .map(|task| IdleTaskDiagnostics {
+                user_hash: include_user_identifiers.then(|| task.key().0.clone()),
+                folder: task.key().1.clone(),
+                subscribers: task.value().subscribers,
+            })
+            .collect::<Vec<_>>();
+        tasks.sort_by(|left, right| left.folder.cmp(&right.folder));
+        tasks.truncate(200);
+        tasks
+    }
 }
 
 impl Default for IdleManager {
@@ -201,12 +225,28 @@ async fn run_idle_session(
                                     },
                                 )
                                 .await;
-                        } else if result.flags_updated > 0 || result.deleted_count > 0 {
+                        }
+                        if result.flags_updated > 0 || result.deleted_count > 0 {
                             event_bus
                                 .publish(
                                     user_hash,
                                     MailEvent::FlagsChanged {
                                         folder: folder.to_string(),
+                                        changes: result.flag_changes,
+                                    },
+                                )
+                                .await;
+                        }
+                        if let Ok(conn) = db::pool::open_user_db(&config.data_dir, user_hash)
+                            && let Ok(Some(folder_state)) = db::folders::get_folder(&conn, folder)
+                        {
+                            event_bus
+                                .publish(
+                                    user_hash,
+                                    MailEvent::FolderStatus {
+                                        folder: folder.to_string(),
+                                        total_count: folder_state.total_count,
+                                        unread_count: folder_state.unread_count,
                                     },
                                 )
                                 .await;
@@ -249,6 +289,7 @@ struct ReconcileResult {
     latest_uid: Option<u32>,
     latest_sender: Option<String>,
     latest_subject: Option<String>,
+    flag_changes: Vec<MessageFlagChange>,
 }
 
 impl ReconcileResult {
@@ -260,6 +301,7 @@ impl ReconcileResult {
             latest_uid: None,
             latest_sender: None,
             latest_subject: None,
+            flag_changes: Vec::new(),
         }
     }
 }
@@ -271,28 +313,42 @@ async fn fetch_new_after_idle(
     config: &AppConfig,
     search_engine: &SearchEngine,
 ) -> (async_imap::Session<ImapStream>, ReconcileResult) {
-    let (cached_modseq, max_cached_uid, cached_count, cached_uid_validity, header_sync) =
+    let (
-        match db::pool::open_user_db(&config.data_dir, user_hash) {
+        cached_modseq,
-            Ok(conn) => {
+        max_cached_uid,
-                let header_sync = match db::header_sync::HeaderSync::capture(&conn) {
+        cached_count,
-                    Ok(sync) => sync,
+        cached_counter_generation,
-                    Err(e) => {
+        cached_uid_validity,
-                        tracing::warn!(error = %e, "IDLE fetch: failed to read header generation");
+        header_sync,
-                        return (session, ReconcileResult::empty());
+    ) = match db::pool::open_user_db(&config.data_dir, user_hash) {
-                    }
+        Ok(conn) => {
-                };
+            let header_sync = match db::header_sync::HeaderSync::capture(&conn) {
-                let cached = db::folders::get_folder(&conn, folder).ok().flatten();
+                Ok(sync) => sync,
-                let modseq = cached.as_ref().map(|f| f.highest_modseq).unwrap_or(0);
+                Err(e) => {
-                let validity = cached.as_ref().map(|f| f.uid_validity).unwrap_or(0);
+                    tracing::warn!(error = %e, "IDLE fetch: failed to read header generation");
-                let max_uid = db::messages::max_uid(&conn, folder).unwrap_or(0);
+                    return (session, ReconcileResult::empty());
-                let count = db::messages::count_messages(&conn, folder).unwrap_or(0);
+                }
-                (modseq, max_uid, count, validity, header_sync)
+            };
-            }
+            let cached = db::folders::get_folder(&conn, folder).ok().flatten();
-            Err(e) => {
+            let modseq = cached.as_ref().map(|f| f.highest_modseq).unwrap_or(0);
-                tracing::warn!(error = %e, "IDLE fetch: failed to open DB");
+            let validity = cached.as_ref().map(|f| f.uid_validity).unwrap_or(0);
-                return (session, ReconcileResult::empty());
+            let counter_generation = cached.as_ref().map(|f| f.counter_generation).unwrap_or(0);
-            }
+            let max_uid = db::messages::max_uid(&conn, folder).unwrap_or(0);
-        };
+            let count = db::messages::count_messages(&conn, folder).unwrap_or(0);
+            (
+                modseq,
+                max_uid,
+                count,
+                counter_generation,
+                validity,
+                header_sync,
+            )
+        }
+        Err(e) => {
+            tracing::warn!(error = %e, "IDLE fetch: failed to open DB");
+            return (session, ReconcileResult::empty());
+        }
+    };
 
     let mailbox = match session.select_condstore(folder).await {
         Ok(mb) => mb,
@@ -303,7 +359,13 @@ async fn fetch_new_after_idle(
     };
 
     let server_exists = mailbox.exists;
-    let server_unseen = mailbox.unseen;
+    let server_unseen = match session.uid_search("UNSEEN").await {
+        Ok(uids) => Some(uids.len() as u32),
+        Err(error) => {
+            tracing::debug!(folder = %folder, error = %error, "IDLE UNSEEN search failed");
+            None
+        }
+    };
     let server_modseq = mailbox.highest_modseq.unwrap_or(0);
     let uid_validity = mailbox.uid_validity.unwrap_or(0);
 
@@ -314,6 +376,18 @@ async fn fetch_new_after_idle(
         return (session, ReconcileResult::empty());
     }
 
+    if let Some(unseen) = server_unseen
+        && let Ok(conn) = db::pool::open_user_db(&config.data_dir, user_hash)
+    {
+        let _ = db::folders::set_folder_counts_if_unchanged(
+            &conn,
+            folder,
+            cached_counter_generation,
+            server_exists,
+            unseen,
+        );
+    }
+
     if server_modseq > 0 && server_modseq == cached_modseq && server_exists == cached_count {
         tracing::debug!(
             user_hash = %user_hash,
@@ -331,6 +405,7 @@ async fn fetch_new_after_idle(
                 Ok(stream) => {
                     let mut stream = std::pin::pin!(stream);
                     let mut items = Vec::new();
+                    let mut complete = true;
                     while let Some(result) = stream.next().await {
                         match result {
                             Ok(fetch) => {
@@ -345,11 +420,12 @@ async fn fetch_new_after_idle(
                                     error = %e,
                                     "IDLE fetch: error reading CHANGEDSINCE stream"
                                 );
+                                complete = false;
                                 break;
                             }
                         }
                     }
-                    Some(items)
+                    complete.then_some(items)
                 }
                 Err(e) => {
                     tracing::warn!(
@@ -378,18 +454,42 @@ async fn fetch_new_after_idle(
                 let sync_keywords = db::mail_preferences::get_preferences(&conn)
                     .map(|prefs| prefs.sync_imap_keywords)
                     .unwrap_or(false);
-                for (uid, flags) in &flag_changes {
+                match header_sync.begin_write(&conn) {
-                    let mut sorted = flags.clone();
+                    Ok(transaction) => {
-                    sorted.sort();
+                        for (uid, flags) in &flag_changes {
-                    let flags_csv = sorted.join(",");
+                            let mut sorted = flags.clone();
-                    if db::messages::update_message_flags(&conn, folder, *uid, &flags_csv).is_ok() {
+                            sorted.sort();
-                        if sync_keywords
+                            let flags_csv = sorted.join(",");
-                            && let Err(error) =
+                            if db::messages::update_message_flags(
-                                db::tags::import_imap_keywords(&conn, *uid, folder, &sorted)
+                                &transaction,
-                        {
+                                folder,
-                            tracing::debug!(uid = uid, error = %error, "IDLE keyword import failed");
+                                *uid,
+                                &flags_csv,
+                            )
+                            .is_ok()
+                            {
+                                if sync_keywords
+                                    && let Err(error) = db::tags::import_imap_keywords(
+                                        &transaction,
+                                        *uid,
+                                        folder,
+                                        &sorted,
+                                    )
+                                {
+                                    tracing::debug!(uid = uid, error = %error, "IDLE keyword import failed");
+                                }
+                                flags_updated += 1;
+                            }
                         }
-                        flags_updated += 1;
+                        if let Err(error) = transaction.commit() {
+                            tracing::debug!(error = %error, "IDLE flag reconciliation commit failed");
+                            flags_updated = 0;
+                            flag_changes.clear();
+                        }
+                    }
+                    Err(error) => {
+                        tracing::debug!(error = %error, "IDLE flag reconciliation discarded stale cache generation");
+                        flag_changes.clear();
                     }
                 }
             }
@@ -399,12 +499,15 @@ async fn fetch_new_after_idle(
                 let uid_range = format!("{}:*", max_cached_uid + 1);
                 new_count = fetch_and_store_headers(
                     &mut session,
-                    user_hash,
+                    HeaderFetchContext {
-                    folder,
+                        user_hash,
-                    config,
+                        folder,
+                        config,
+                        search_engine,
+                        header_sync,
+                    },
                     &uid_range,
                     max_cached_uid,
-                    header_sync,
                 )
                 .await;
             }
@@ -430,22 +533,16 @@ async fn fetch_new_after_idle(
             if let Ok(conn) = db::pool::open_user_db(&config.data_dir, user_hash)
                 && let Ok(transaction) = header_sync.begin_write(&conn)
             {
-                let _ = db::folders::update_folder_sync_status(
+                let _ = db::folders::update_folder_sync_cursor(
-                    &conn,
+                    &transaction,
                     folder,
                     uid_validity,
-                    server_exists,
                     server_modseq,
                 );
-                if let Some(unseen) = server_unseen {
-                    let _ = db::folders::set_unread_count(&conn, folder, unseen);
-                } else {
-                    let _ = db::folders::refresh_unread_count(&conn, folder);
-                }
                 if has_new && new_count == 0 {
-                    let _ = db::folders::invalidate_folder_freshness(&conn, folder);
+                    let _ = db::folders::invalidate_folder_freshness(&transaction, folder);
                 } else {
-                    let _ = db::folders::mark_folder_messages_fresh(&conn, folder);
+                    let _ = db::folders::mark_folder_messages_fresh(&transaction, folder);
                 }
                 let _ = transaction.commit();
             }
@@ -470,53 +567,136 @@ async fn fetch_new_after_idle(
                     latest_uid,
                     latest_sender,
                     latest_subject,
+                    flag_changes: flag_changes
+                        .into_iter()
+                        .map(|(uid, mut flags)| {
+                            flags.sort();
+                            MessageFlagChange { uid, flags }
+                        })
+                        .collect(),
                 },
             );
         }
     }
 
-    let cached_uids: std::collections::HashSet<u32> =
+    let cached_state = match db::pool::open_user_db(&config.data_dir, user_hash) {
-        match db::pool::open_user_db(&config.data_dir, user_hash) {
+        Ok(conn) => db::messages::get_all_uids_and_flags(&conn, folder).unwrap_or_default(),
-            Ok(conn) => {
+        Err(e) => {
-                let uids_flags =
+            tracing::warn!(error = %e, "IDLE fetch: failed to open DB for fallback");
-                    db::messages::get_all_uids_and_flags(&conn, folder).unwrap_or_default();
+            return (session, ReconcileResult::empty());
-                uids_flags.iter().map(|(uid, _)| *uid).collect()
+        }
-            }
+    };
-            Err(e) => {
+    let cached_uids = cached_state
-                tracing::warn!(error = %e, "IDLE fetch: failed to open DB for fallback");
+        .iter()
-                return (session, ReconcileResult::empty());
+        .map(|(uid, _)| *uid)
-            }
+        .collect::<std::collections::HashSet<_>>();
-        };
+    let cached_flags = cached_state
+        .into_iter()
+        .map(|(uid, flags)| {
+            let mut normalized = flags
+                .split(',')
+                .filter(|flag| !flag.is_empty())
+                .map(str::to_string)
+                .collect::<Vec<_>>();
+            normalized.sort();
+            normalized.dedup();
+            (uid, normalized)
+        })
+        .collect::<std::collections::HashMap<_, _>>();
 
-    let imap_uids: Option<std::collections::HashSet<u32>> =
+    let imap_state: Option<std::collections::HashMap<u32, Vec<String>>> = match session
-        match session.uid_fetch("1:*", "UID").await {
+        .uid_fetch("1:*", "UID FLAGS")
-            Ok(stream) => {
+        .await
-                let mut stream = std::pin::pin!(stream);
+    {
-                let mut uids = std::collections::HashSet::new();
+        Ok(stream) => {
-                while let Some(result) = stream.next().await {
+            let mut stream = std::pin::pin!(stream);
-                    match result {
+            let mut state = std::collections::HashMap::new();
-                        Ok(fetch) => {
+            let mut complete = true;
-                            if let Some(uid) = fetch.uid {
+            while let Some(result) = stream.next().await {
-                                uids.insert(uid);
+                match result {
-                            }
+                    Ok(fetch) => {
-                        }
+                        if let Some(uid) = fetch.uid {
-                        Err(e) => {
+                            let mut flags = fetch
-                            tracing::warn!(error = %e, "IDLE fetch: error reading UID stream");
+                                .flags()
-                            break;
+                                .map(|flag| flag_to_string(&flag))
+                                .collect::<Vec<_>>();
+                            flags.sort();
+                            flags.dedup();
+                            state.insert(uid, flags);
                         }
                     }
+                    Err(e) => {
+                        tracing::warn!(error = %e, "IDLE fetch: error reading UID/FLAGS stream");
+                        complete = false;
+                        break;
+                    }
                 }
-                Some(uids)
             }
-            Err(e) => {
+            complete.then_some(state)
-                tracing::warn!(error = %e, "IDLE fetch: uid_fetch(UIDs) failed");
+        }
-                None
+        Err(e) => {
-            }
+            tracing::warn!(error = %e, "IDLE fetch: uid_fetch(UID FLAGS) failed");
-        };
+            None
+        }
+    };
 
-    let Some(imap_uids) = imap_uids else {
+    let Some(imap_state) = imap_state else {
         return (session, ReconcileResult::empty());
     };
+    let imap_uids = imap_state
+        .keys()
+        .copied()
+        .collect::<std::collections::HashSet<_>>();
+
+    let mut flag_changes = cached_flags
+        .iter()
+        .filter_map(|(uid, cached)| {
+            imap_state
+                .get(uid)
+                .filter(|server| *server != cached)
+                .map(|server| (*uid, server.clone()))
+        })
+        .collect::<Vec<_>>();
+    flag_changes.sort_by_key(|(uid, _)| *uid);
+    let mut flags_updated = 0u32;
+    if !flag_changes.is_empty()
+        && let Ok(conn) = db::pool::open_user_db(&config.data_dir, user_hash)
+    {
+        let sync_keywords = db::mail_preferences::get_preferences(&conn)
+            .map(|prefs| prefs.sync_imap_keywords)
+            .unwrap_or(false);
+        match header_sync.begin_write(&conn) {
+            Ok(transaction) => {
+                for (uid, flags) in &flag_changes {
+                    if db::messages::update_message_flags(
+                        &transaction,
+                        folder,
+                        *uid,
+                        &flags.join(","),
+                    )
+                    .is_ok()
+                    {
+                        if sync_keywords
+                            && let Err(error) =
+                                db::tags::import_imap_keywords(&transaction, *uid, folder, flags)
+                        {
+                            tracing::debug!(uid = uid, error = %error, "IDLE fallback keyword import failed");
+                        }
+                        flags_updated += 1;
+                    }
+                }
+                if let Err(error) = transaction.commit() {
+                    tracing::debug!(error = %error, "IDLE fallback flag reconciliation commit failed");
+                    flags_updated = 0;
+                    flag_changes.clear();
+                }
+            }
+            Err(error) => {
+                tracing::debug!(error = %error, "IDLE fallback flag reconciliation discarded stale cache generation");
+                flag_changes.clear();
+            }
+        }
+    }
 
     let has_new = imap_uids.iter().any(|&uid| uid > max_cached_uid);
     let mut new_count = 0u32;
@@ -524,12 +704,15 @@ async fn fetch_new_after_idle(
         let uid_range = format!("{}:*", max_cached_uid + 1);
         new_count = fetch_and_store_headers(
             &mut session,
-            user_hash,
+            HeaderFetchContext {
-            folder,
+                user_hash,
-            config,
+                folder,
+                config,
+                search_engine,
+                header_sync,
+            },
             &uid_range,
             max_cached_uid,
-            header_sync,
         )
         .await;
     }
@@ -553,22 +736,16 @@ async fn fetch_new_after_idle(
     if let Ok(conn) = db::pool::open_user_db(&config.data_dir, user_hash)
         && let Ok(transaction) = header_sync.begin_write(&conn)
     {
-        let _ = db::folders::update_folder_sync_status(
+        let _ = db::folders::update_folder_sync_cursor(
-            &conn,
+            &transaction,
             folder,
             uid_validity,
-            server_exists,
             server_modseq,
         );
-        if let Some(unseen) = server_unseen {
-            let _ = db::folders::set_unread_count(&conn, folder, unseen);
-        } else {
-            let _ = db::folders::refresh_unread_count(&conn, folder);
-        }
         if has_new && new_count == 0 {
-            let _ = db::folders::invalidate_folder_freshness(&conn, folder);
+            let _ = db::folders::invalidate_folder_freshness(&transaction, folder);
         } else {
-            let _ = db::folders::mark_folder_messages_fresh(&conn, folder);
+            let _ = db::folders::mark_folder_messages_fresh(&transaction, folder);
         }
         let _ = transaction.commit();
     }
@@ -579,10 +756,11 @@ async fn fetch_new_after_idle(
         (None, None, None)
     };
 
-    if new_count > 0 || deleted_count > 0 {
+    if flags_updated > 0 || new_count > 0 || deleted_count > 0 {
         tracing::info!(
             user_hash = %user_hash,
             folder = %folder,
+            flags_updated = flags_updated,
             new = new_count,
             deleted = deleted_count,
             "Reconciled cache after IDLE (full scan)"
@@ -593,11 +771,15 @@ async fn fetch_new_after_idle(
         session,
         ReconcileResult {
             new_count,
-            flags_updated: 0,
+            flags_updated,
             deleted_count,
             latest_uid,
             latest_sender,
             latest_subject,
+            flag_changes: flag_changes
+                .into_iter()
+                .map(|(uid, flags)| MessageFlagChange { uid, flags })
+                .collect(),
         },
     )
 }
@@ -634,15 +816,27 @@ fn lookup_latest_message(
     }
 }
 
+struct HeaderFetchContext<'a> {
+    user_hash: &'a str,
+    folder: &'a str,
+    config: &'a AppConfig,
+    search_engine: &'a SearchEngine,
+    header_sync: db::header_sync::HeaderSync,
+}
+
 async fn fetch_and_store_headers(
     session: &mut async_imap::Session<ImapStream>,
-    user_hash: &str,
+    context: HeaderFetchContext<'_>,
-    folder: &str,
-    config: &AppConfig,
     uid_range: &str,
     min_uid: u32,
-    header_sync: db::header_sync::HeaderSync,
 ) -> u32 {
+    let HeaderFetchContext {
+        user_hash,
+        folder,
+        config,
+        search_engine,
+        header_sync,
+    } = context;
     let fetches: Option<Vec<_>> = match session
         .uid_fetch(
             uid_range,
@@ -653,16 +847,18 @@ async fn fetch_and_store_headers(
         Ok(stream) => {
             let mut stream = std::pin::pin!(stream);
             let mut items = Vec::new();
+            let mut complete = true;
             while let Some(result) = stream.next().await {
                 match result {
                     Ok(fetch) => items.push(fetch),
                     Err(e) => {
                         tracing::warn!(error = %e, "IDLE fetch: error reading header stream");
+                        complete = false;
                         break;
                     }
                 }
             }
-            Some(items)
+            complete.then_some(items)
         }
         Err(e) => {
             tracing::warn!(error = %e, "IDLE fetch: uid_fetch(headers) failed");
@@ -684,6 +880,11 @@ async fn fetch_and_store_headers(
         let sync_keywords = db::mail_preferences::get_preferences(&conn)
             .map(|prefs| prefs.sync_imap_keywords)
             .unwrap_or(false);
+        let user_index = if search_engine.is_enabled() && !UserIndex::is_excluded_folder(folder) {
+            search_engine.open_user_index(user_hash).ok()
+        } else {
+            None
+        };
         for fetch in &fetches {
             let uid = match fetch.uid {
                 Some(u) if u > min_uid => u,
@@ -787,7 +988,7 @@ async fn fetch_and_store_headers(
             let flags_csv = flags.join(",");
 
             if let Err(e) = db::messages::upsert_message(
-                &conn,
+                &transaction,
                 folder,
                 uid,
                 message_id.as_deref(),
@@ -808,7 +1009,7 @@ async fn fetch_and_store_headers(
                 tracing::warn!(uid = uid, error = %e, "IDLE fetch: failed to upsert message");
             } else {
                 if let Err(e) = db::contacts::populate_known_addresses(
-                    &conn,
+                    &transaction,
                     from_address,
                     from_name,
                     &to_json,
@@ -817,10 +1018,30 @@ async fn fetch_and_store_headers(
                     tracing::warn!(uid = uid, error = %e, "IDLE fetch: failed to populate known addresses");
                 }
                 if sync_keywords
-                    && let Err(error) = db::tags::import_imap_keywords(&conn, uid, folder, &flags)
+                    && let Err(error) =
+                        db::tags::import_imap_keywords(&transaction, uid, folder, &flags)
                 {
                     tracing::debug!(uid = uid, error = %error, "IDLE keyword import failed");
                 }
+                if let Some(index) = user_index.as_ref()
+                    && let Err(error) = index.index_message_with_connection(
+                        &transaction,
+                        &IndexableMessage {
+                            uid,
+                            folder: folder.to_string(),
+                            subject: subject_str.to_string(),
+                            from_address: from_address.to_string(),
+                            from_name: from_name.to_string(),
+                            to_addresses: to_json.clone(),
+                            body_text: String::new(),
+                            date_epoch: db::messages::parse_date_to_epoch_public(date_str),
+                            has_attachments: has_attach,
+                        },
+                    )
+                {
+                    tracing::warn!(uid = uid, error = %error, "IDLE fetch: failed to enqueue search indexing");
+                    return 0;
+                }
                 new_count += 1;
             }
         }
@@ -888,6 +1109,7 @@ async fn fetch_uids_and_remove_deleted(
             Ok(stream) => {
                 let mut stream = std::pin::pin!(stream);
                 let mut uids = std::collections::HashSet::new();
+                let mut complete = true;
                 while let Some(result) = stream.next().await {
                     match result {
                         Ok(fetch) => {
@@ -900,11 +1122,12 @@ async fn fetch_uids_and_remove_deleted(
                                 error = %e,
                                 "IDLE fetch: error reading UID stream for deletion check"
                             );
+                            complete = false;
                             break;
                         }
                     }
                 }
-                Some(uids)
+                complete.then_some(uids)
             }
             Err(e) => {
                 tracing::warn!(

src/realtime/sync.rs

@@ -5,12 +5,10 @@ use crate::config::AppConfig;
 use crate::db;
 use crate::email_theme;
 use crate::imap::client::{ImapClient, ImapCredentials};
-use crate::realtime::events::{EventBus, MailEvent};
+use crate::realtime::events::{EventBus, MailEvent, MessageFlagChange};
 use crate::search::engine::UserIndex;
 use crate::search::engine::{IndexableMessage, SearchEngine};
 
-const SYNC_INTERVAL_SECS: u64 = 30;
-
 pub async fn sync_loop(
     user_hash: String,
     creds: ImapCredentials,
@@ -19,7 +17,8 @@ pub async fn sync_loop(
     event_bus: Arc<EventBus>,
     search_engine: Arc<SearchEngine>,
 ) {
-    let mut interval = tokio::time::interval(std::time::Duration::from_secs(SYNC_INTERVAL_SECS));
+    let mut interval =
+        tokio::time::interval(std::time::Duration::from_secs(config.sync.interval_secs));
     interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
 
     loop {
@@ -62,28 +61,81 @@ async fn run_sync(
                     uid_validity: f.uid_validity,
                     highest_modseq: f.highest_modseq,
                     total_count: f.total_count,
+                    unread_count: f.unread_count,
+                    counter_generation: f.counter_generation,
+                    flags: f.flags,
                 })
                 .collect::<Vec<_>>())
         })
         .await?;
 
     let mut any_changes = false;
+    let folder_names = folder_snapshots
+        .iter()
+        .filter(|folder| !folder.is_noselect())
+        .map(|folder| folder.name.clone())
+        .collect::<Vec<_>>();
+    let mut batched_statuses = imap_client
+        .folder_statuses_extended(creds, &folder_names)
+        .await
+        .unwrap_or_default()
+        .into_iter()
+        .collect::<HashMap<_, _>>();
 
     for folder in &folder_snapshots {
         let folder_name = &folder.name;
+        if folder.is_noselect() {
+            continue;
+        }
 
-        let status = match imap_client.folder_status_extended(creds, folder_name).await {
+        let status = if let Some(status) = batched_statuses.remove(folder_name) {
-            Ok(s) => s,
+            status
-            Err(e) => {
+        } else {
-                tracing::debug!(
+            match imap_client.folder_status_extended(creds, folder_name).await {
-                    folder = %folder_name,
+                Ok(status) => status,
-                    error = %e,
+                Err(error) => {
-                    "Skipping folder sync (STATUS failed)"
+                    tracing::debug!(
-                );
+                        folder = %folder_name,
-                continue;
+                        error = %error,
+                        "Skipping folder sync (STATUS failed)"
+                    );
+                    continue;
+                }
             }
         };
 
+        if status.exists != folder.total_count || status.unseen != folder.unread_count {
+            let name = folder_name.clone();
+            let expected_generation = folder.counter_generation;
+            let total_count = status.exists;
+            let unread_count = status.unseen;
+            let applied = database
+                .run(move |conn| {
+                    db::folders::set_folder_counts_if_unchanged(
+                        conn,
+                        &name,
+                        expected_generation,
+                        total_count,
+                        unread_count,
+                    )
+                })
+                .await?;
+            if applied {
+                event_bus
+                    .publish(
+                        user_hash,
+                        MailEvent::FolderStatus {
+                            folder: folder_name.clone(),
+                            total_count,
+                            unread_count,
+                        },
+                    )
+                    .await;
+            } else {
+                tracing::debug!(folder = %folder_name, "Skipped stale periodic STATUS counters");
+            }
+        }
+
         if folder.uid_validity != 0 && status.uid_validity != folder.uid_validity {
             tracing::info!(
                 folder = %folder_name,
@@ -162,7 +214,13 @@ async fn run_sync(
     }
 
     if any_changes {
-        event_bus.publish(user_hash, MailEvent::FolderUpdated).await;
+        tracing::debug!(user_hash = %user_hash, "Periodic sync applied message changes");
+    }
+
+    if let Ok(pending) = database.run(db::folders::pending_message_sync_count).await {
+        event_bus
+            .publish(user_hash, MailEvent::SyncInventory { pending })
+            .await;
     }
 
     if search_engine.is_enabled()
@@ -182,8 +240,6 @@ async fn run_sync(
     Ok(())
 }
 
-const DEEP_INDEX_BATCH: u32 = 10;
-
 async fn index_message_bodies(
     user_hash: &str,
     creds: &ImapCredentials,
@@ -193,12 +249,18 @@ async fn index_message_bodies(
     search_engine: Arc<SearchEngine>,
 ) -> Result<(), String> {
     let database = db::pool::UserDb::new(&config.data_dir, user_hash);
-    let unindexed = database
+    let force_deep_index = config.search.deep_index;
-        .run(|conn| {
+    let deep_index_batch_size = config.sync.deep_index_batch_size;
-            if !db::display_preferences::get_preferences(conn)?.deep_index {
+    let (pending_before, unindexed) = database
-                return Ok(Vec::new());
+        .run(move |conn| {
+            let account_deep_index = db::display_preferences::get_preferences(conn)?.deep_index;
+            if !force_deep_index && !account_deep_index {
+                return Ok((0, Vec::new()));
             }
-            db::messages::get_unindexed_messages(conn, DEEP_INDEX_BATCH)
+            Ok((
+                db::messages::count_unindexed_messages(conn)?,
+                db::messages::get_unindexed_messages(conn, deep_index_batch_size)?,
+            ))
         })
         .await?;
 
@@ -208,7 +270,7 @@ async fn index_message_bodies(
                 user_hash,
                 MailEvent::IndexingStatus {
                     active: false,
-                    pending: 0,
+                    pending: pending_before,
                 },
             )
             .await;
@@ -220,7 +282,7 @@ async fn index_message_bodies(
             user_hash,
             MailEvent::IndexingStatus {
                 active: true,
-                pending: unindexed.len() as u32,
+                pending: pending_before,
             },
         )
         .await;
@@ -297,12 +359,16 @@ async fn index_message_bodies(
     }
     .await;
 
+    let pending_after = database
+        .run(db::messages::count_unindexed_messages)
+        .await
+        .unwrap_or(pending_before);
     event_bus
         .publish(
             user_hash,
             MailEvent::IndexingStatus {
                 active: false,
-                pending: 0,
+                pending: pending_after,
             },
         )
         .await;
@@ -314,6 +380,17 @@ struct FolderSnapshot {
     uid_validity: u32,
     highest_modseq: u64,
     total_count: u32,
+    unread_count: u32,
+    counter_generation: u64,
+    flags: String,
+}
+
+impl FolderSnapshot {
+    fn is_noselect(&self) -> bool {
+        self.flags
+            .split(',')
+            .any(|flag| flag.trim().eq_ignore_ascii_case("\\Noselect"))
+    }
 }
 
 fn store_headers(
@@ -551,7 +628,7 @@ async fn sync_condstore(
     let search_engine_for_write = Arc::clone(search_engine);
     let search_user_hash = user_hash.to_owned();
     let headers_for_write = new_headers;
-    let (folder_changed, non_new_change) = database
+    let (folder_changed, non_new_change, flag_changes) = database
         .run(move |conn| {
             let sync_keywords = db::mail_preferences::get_preferences(conn)
                 .map(|prefs| prefs.sync_imap_keywords)
@@ -560,9 +637,14 @@ async fn sync_condstore(
                 .unchecked_transaction()
                 .map_err(|error| error.to_string())?;
             let mut non_new_change = !changed.is_empty();
+            let mut flag_changes = Vec::with_capacity(changed.len());
             for (uid, mut flags) in changed {
                 flags.sort();
                 db::messages::update_message_flags(&transaction, &name, uid, &flags.join(","))?;
+                flag_changes.push(MessageFlagChange {
+                    uid,
+                    flags: flags.clone(),
+                });
                 if sync_keywords {
                     db::tags::import_imap_keywords(&transaction, uid, &name, &flags)?;
                 }
@@ -588,19 +670,18 @@ async fn sync_condstore(
                 &search_engine_for_write,
                 &search_user_hash,
             )?;
+
             let modseq = if new_modseq > 0 {
                 new_modseq
             } else {
-                status.highest_modseq
+                cached_modseq
             };
-            db::folders::update_folder_sync_status(
+            db::folders::update_folder_sync_cursor(
                 &transaction,
                 &name,
                 status.uid_validity,
-                status.exists,
                 modseq,
             )?;
-            db::folders::set_unread_count(&transaction, &name, status.unseen)?;
             if has_unfetched_new {
                 db::folders::invalidate_folder_freshness(&transaction, &name)?;
             } else if cache_initialized {
@@ -610,6 +691,7 @@ async fn sync_condstore(
             Ok((
                 non_new_change || !headers_for_write.is_empty(),
                 non_new_change,
+                flag_changes,
             ))
         })
         .await?;
@@ -635,6 +717,7 @@ async fn sync_condstore(
                 user_hash,
                 MailEvent::FlagsChanged {
                     folder: folder_name.to_string(),
+                    changes: flag_changes,
                 },
             )
             .await;
@@ -703,16 +786,21 @@ async fn sync_full(
         let status = status.clone();
         database
             .run(move |conn| {
-                db::folders::update_folder_sync_status(
+                let safe_modseq = if status.exists == 0 {
+                    status.highest_modseq
+                } else {
+                    0
+                };
+                db::folders::update_folder_sync_cursor(
                     conn,
                     &name,
                     status.uid_validity,
-                    status.exists,
+                    safe_modseq,
-                    status.highest_modseq,
                 )?;
-                db::folders::set_unread_count(conn, &name, status.unseen)?;
+                if has_unfetched_new || status.exists > 0 {
-                if has_unfetched_new {
                     db::folders::invalidate_folder_freshness(conn, &name)?;
+                } else {
+                    db::folders::mark_folder_messages_fresh(conn, &name)?;
                 }
                 Ok(())
             })
@@ -740,7 +828,7 @@ async fn sync_full(
     let search_engine_for_write = Arc::clone(search_engine);
     let search_user_hash = user_hash.to_owned();
     let headers_for_write = new_headers;
-    let non_new_change = database
+    let (non_new_change, flag_changes) = database
         .run(move |conn| {
             let folder_name = &name;
             let sync_keywords = db::mail_preferences::get_preferences(conn)
@@ -758,6 +846,7 @@ async fn sync_full(
                 .collect();
 
             let mut non_new_change = false;
+            let mut flag_changes = Vec::new();
             for (uid, cached_flags_csv) in &cached {
                 match imap_map.get(uid) {
                     None => {
@@ -788,6 +877,10 @@ async fn sync_full(
                                 *uid,
                                 &imap_flags_csv,
                             )?;
+                            flag_changes.push(MessageFlagChange {
+                                uid: *uid,
+                                flags: imap_flags.clone(),
+                            });
                             non_new_change = true;
                         }
                         if sync_keywords {
@@ -809,21 +902,20 @@ async fn sync_full(
                 &search_engine_for_write,
                 &search_user_hash,
             )?;
-            db::folders::update_folder_sync_status(
+
+            db::folders::update_folder_sync_cursor(
                 &transaction,
                 folder_name,
                 status.uid_validity,
-                status.exists,
                 status.highest_modseq,
             )?;
-            db::folders::set_unread_count(&transaction, folder_name, status.unseen)?;
             if has_unfetched_new {
                 db::folders::invalidate_folder_freshness(&transaction, folder_name)?;
             } else if cache_initialized {
                 db::folders::mark_folder_messages_fresh(&transaction, folder_name)?;
             }
             transaction.commit().map_err(|error| error.to_string())?;
-            Ok(non_new_change)
+            Ok((non_new_change, flag_changes))
         })
         .await?;
 
@@ -848,6 +940,7 @@ async fn sync_full(
                 user_hash,
                 MailEvent::FlagsChanged {
                     folder: folder_name.to_string(),
+                    changes: flag_changes,
                 },
             )
             .await;

src/routes/auth.rs

@@ -18,19 +18,27 @@ pub const BROWSER_COOKIE: &str = "rustbox_browser";
 #[serde(rename_all = "camelCase")]
 pub struct AuthPolicyResponse {
     remember_me_enabled: bool,
-    remember_me_days: u64,
+}
-    session_timeout_hours: u64,
+
+pub async fn auth_policy(Extension(config): Extension<Arc<AppConfig>>) -> Json<AuthPolicyResponse> {
+    Json(AuthPolicyResponse {
+        remember_me_enabled: config.remember_me_enabled,
+    })
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SessionPolicyResponse {
     pgp_enabled: bool,
     sieve_enabled: bool,
     diagnostics_enabled: bool,
     about_enabled: bool,
 }
 
-pub async fn auth_policy(Extension(config): Extension<Arc<AppConfig>>) -> Json<AuthPolicyResponse> {
+pub async fn session_policy(
-    Json(AuthPolicyResponse {
+    Extension(config): Extension<Arc<AppConfig>>,
-        remember_me_enabled: config.remember_me_enabled,
+) -> Json<SessionPolicyResponse> {
-        remember_me_days: config.remember_me_days,
+    Json(SessionPolicyResponse {
-        session_timeout_hours: config.session_timeout_hours,
         pgp_enabled: config.pgp_enabled,
         sieve_enabled: config.sieve_enabled,
         diagnostics_enabled: config.diagnostics_enabled,

src/routes/contacts.rs

@@ -624,7 +624,6 @@ pub async fn get_contact_photo_handler(
     Response::builder()
         .header("content-type", content_type)
         .header("cache-control", "private, max-age=3600")
-        .header("x-content-type-options", "nosniff")
         .body(axum::body::Body::from(data))
         .map_err(|e| AppError::InternalError(format!("Failed to build photo response: {e}")))
 }

src/routes/diagnostics.rs

@@ -9,6 +9,7 @@ use crate::config::AppConfig;
 use crate::db;
 use crate::error::AppError;
 use crate::imap::client::{ImapClient, ImapCredentials};
+use crate::realtime::events::{EventBus, MailEvent};
 use crate::realtime::idle::IdleManager;
 use crate::search::engine::{IndexableMessage, SearchEngine, UserIndex};
 use crate::smtp::client::{SmtpClient, SmtpCredentials};
@@ -45,6 +46,7 @@ pub struct SmtpDiagnosticsResponse {
 #[serde(rename_all = "camelCase")]
 pub struct SearchDiagnosticsResponse {
     backend: String,
+    deep_index_enabled: bool,
     indexed_documents: usize,
     cached_messages: usize,
     cached_bodies: usize,
@@ -259,11 +261,14 @@ pub async fn search_diagnostics(
     let data_dir = config.data_dir.clone();
     let user_hash = session.user_hash.clone();
     let db_user_hash = user_hash.clone();
+    let force_deep_index = config.search.deep_index;
 
-    let (cached_messages, cached_bodies, excluded_messages, outbox) =
+    let (deep_index_enabled, cached_messages, cached_bodies, excluded_messages, outbox) =
         tokio::task::spawn_blocking(move || -> Result<_, String> {
             let conn = db::pool::open_user_db(&data_dir, &db_user_hash)
                 .map_err(|e| format!("Database error: {e}"))?;
+            let account_deep_index = db::display_preferences::get_preferences(&conn)?.deep_index;
+            let deep_index_enabled = force_deep_index || account_deep_index;
             let sources = db::messages::list_index_source_messages(&conn)?;
             let cached_messages = sources.len();
             let excluded_messages = sources
@@ -274,7 +279,13 @@ pub async fn search_diagnostics(
                 .query_row(crate::dbq!(routes_diagnostics::Q_003), [], |row| row.get(0))
                 .map_err(|e| format!("Failed to count cached bodies: {e}"))?;
             let outbox = db::search_outbox::stats(&conn).unwrap_or_default();
-            Ok((cached_messages, cached_bodies, excluded_messages, outbox))
+            Ok((
+                deep_index_enabled,
+                cached_messages,
+                cached_bodies,
+                excluded_messages,
+                outbox,
+            ))
         })
         .await
         .map_err(|e| AppError::InternalError(format!("Search diagnostics task failed: {e}")))?
@@ -293,6 +304,7 @@ pub async fn search_diagnostics(
 
     let stats = SearchDiagnosticsResponse {
         backend: search_engine.backend_name().to_string(),
+        deep_index_enabled,
         indexed_documents,
         cached_messages,
         cached_bodies,
@@ -309,6 +321,7 @@ pub async fn rebuild_search_index(
     Extension(session): Extension<SessionState>,
     Extension(config): Extension<Arc<AppConfig>>,
     Extension(search_engine): Extension<Arc<SearchEngine>>,
+    Extension(event_bus): Extension<Arc<EventBus>>,
 ) -> Result<Response, AppError> {
     if !search_engine.is_enabled() {
         return Err(AppError::ServiceUnavailable(
@@ -330,13 +343,32 @@ pub async fn rebuild_search_index(
     .map_err(|e| AppError::InternalError(format!("Search rebuild task failed: {e}")))?
     .map_err(AppError::InternalError)?;
 
-    let index = search_engine
+    event_bus
-        .open_user_index(&user_hash)
+        .publish(
-        .map_err(AppError::InternalError)?;
+            &user_hash,
-    let indexed_documents = index
+            MailEvent::IndexingStatus {
-        .rebuild_from_messages(&messages)
+                active: true,
-        .await
+                pending: source_messages.min(u32::MAX as usize) as u32,
-        .map_err(AppError::InternalError)?;
+            },
+        )
+        .await;
+
+    let rebuild_result = match search_engine.open_user_index(&user_hash) {
+        Ok(index) => index.rebuild_from_messages(&messages).await,
+        Err(error) => Err(error),
+    };
+
+    event_bus
+        .publish(
+            &user_hash,
+            MailEvent::IndexingStatus {
+                active: false,
+                pending: 0,
+            },
+        )
+        .await;
+
+    let indexed_documents = rebuild_result.map_err(AppError::InternalError)?;
 
     Ok(Json(SearchRebuildResponse {
         status: "rebuilt",

src/routes/folder_counts.rs

@@ -0,0 +1,120 @@
+use crate::config::AppConfig;
+use crate::db;
+use crate::error::AppError;
+use crate::imap::client::{ImapClient, ImapCredentials};
+
+pub(crate) type FolderCountSnapshot = Option<(u32, u32, u64)>;
+
+pub(crate) fn snapshot(
+    config: &AppConfig,
+    user_hash: &str,
+    folder: &str,
+) -> Result<FolderCountSnapshot, AppError> {
+    let conn = db::pool::open_user_db(&config.data_dir, user_hash)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    let state = db::folders::get_folder(&conn, folder)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    Ok(state.map(|folder| {
+        (
+            folder.total_count,
+            folder.unread_count,
+            folder.counter_generation,
+        )
+    }))
+}
+
+pub(crate) fn current_counts(
+    config: &AppConfig,
+    user_hash: &str,
+    folder: &str,
+) -> Result<Option<(u32, u32)>, AppError> {
+    Ok(snapshot(config, user_hash, folder)?.map(|(total, unread, _generation)| (total, unread)))
+}
+
+pub(crate) async fn reconcile_after_mutation(
+    config: &AppConfig,
+    user_hash: &str,
+    imap_client: &dyn ImapClient,
+    creds: &ImapCredentials,
+    folder: &str,
+    mut expected: FolderCountSnapshot,
+) -> Result<Option<(u32, u32)>, AppError> {
+    for attempt in 0..2 {
+        let status = match imap_client.folder_status_extended(creds, folder).await {
+            Ok(status) => status,
+            Err(error) => {
+                tracing::debug!(
+                    folder = %folder,
+                    attempt,
+                    error = %error,
+                    "Could not refresh authoritative folder counters after IMAP mutation"
+                );
+                return Ok(None);
+            }
+        };
+
+        let conn = db::pool::open_user_db(&config.data_dir, user_hash)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+
+        let applied =
+            if let Some((_expected_total, _expected_unread, expected_generation)) = expected {
+                db::folders::set_folder_counts_if_unchanged(
+                    &conn,
+                    folder,
+                    expected_generation,
+                    status.exists,
+                    status.unseen,
+                )
+                .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?
+            } else {
+                db::folders::set_folder_counts(&conn, folder, status.exists, status.unseen)
+                    .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+                true
+            };
+
+        if applied {
+            return Ok(Some((status.exists, status.unseen)));
+        }
+
+        expected = db::folders::get_folder(&conn, folder)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?
+            .map(|state| {
+                (
+                    state.total_count,
+                    state.unread_count,
+                    state.counter_generation,
+                )
+            });
+    }
+
+    current_counts(config, user_hash, folder)
+}
+
+pub(crate) fn set_if_snapshot_matches(
+    config: &AppConfig,
+    user_hash: &str,
+    folder: &str,
+    expected: FolderCountSnapshot,
+    total_count: u32,
+    unread_count: u32,
+) -> Result<(u32, u32), AppError> {
+    let conn = db::pool::open_user_db(&config.data_dir, user_hash)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+
+    if let Some((_expected_total, _expected_unread, expected_generation)) = expected {
+        let _ = db::folders::set_folder_counts_if_unchanged(
+            &conn,
+            folder,
+            expected_generation,
+            total_count,
+            unread_count,
+        )
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    }
+
+    let state = db::folders::get_folder(&conn, folder)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    Ok(state
+        .map(|state| (state.total_count, state.unread_count))
+        .unwrap_or((total_count, unread_count)))
+}

src/routes/folder_mgmt.rs

@@ -10,6 +10,8 @@ use crate::config::AppConfig;
 use crate::db;
 use crate::error::AppError;
 use crate::imap::client::{ImapClient, ImapCredentials};
+use crate::realtime::events::{EventBus, MailEvent};
+use crate::routes::folder_counts;
 use crate::search::engine::SearchEngine;
 
 #[derive(Deserialize)]
@@ -32,6 +34,14 @@ struct MessageResponse {
     status: &'static str,
 }
 
+#[derive(Serialize)]
+struct FolderCounterResponse {
+    status: &'static str,
+    total_count: u32,
+    unread_count: u32,
+    through_uid: Option<u32>,
+}
+
 const SYSTEM_FOLDERS: &[&str] = &["INBOX", "Sent", "Drafts", "Trash", "Junk", "Spam"];
 
 fn is_system_folder(name: &str) -> bool {
@@ -188,25 +198,96 @@ pub async fn mark_all_read(
     Extension(session): Extension<SessionState>,
     Extension(config): Extension<Arc<AppConfig>>,
     Extension(imap_client): Extension<Arc<dyn ImapClient>>,
+    Extension(event_bus): Extension<Arc<EventBus>>,
     Path(name): Path<String>,
 ) -> Result<Response, AppError> {
     let creds = build_creds(&session, &config)?;
+    let counter_snapshot = folder_counts::snapshot(&config, &session.user_hash, &name)?;
+    let cached_flags_snapshot = {
+        let conn = db::pool::open_user_db(&config.data_dir, &session.user_hash)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+        db::messages::get_all_uids_and_flags(&conn, &name)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?
+    };
+    let through_uid = cached_flags_snapshot.iter().map(|(uid, _)| *uid).max();
     imap_client
         .mark_all_read(&creds, &name)
         .await
         .map_err(|e| AppError::ServiceUnavailable(format!("IMAP mark-all-read failed: {e}")))?;
 
+    let authoritative_counts = folder_counts::reconcile_after_mutation(
+        &config,
+        &session.user_hash,
+        imap_client.as_ref(),
+        &creds,
+        &name,
+        counter_snapshot,
+    )
+    .await?;
+
     let conn = db::pool::open_user_db(&config.data_dir, &session.user_hash)
         .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
-    conn.execute(
+    for (uid, flags_csv) in cached_flags_snapshot {
-        crate::dbq!(routes_folder_mgmt::Q_001),
+        let mut flags = flags_csv
-        crate::db::pool::params![&name, "\\Seen"],
+            .split(',')
-    )
+            .filter(|flag| !flag.is_empty())
-    .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+            .map(str::to_string)
-    conn.execute(crate::dbq!(routes_folder_mgmt::Q_002), [&name])
+            .collect::<Vec<_>>();
-        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+        if !flags.iter().any(|flag| flag == "\\Seen") {
+            flags.push("\\Seen".to_string());
+            flags.sort();
+            flags.dedup();
+            db::messages::update_message_flags(&conn, &name, uid, &flags.join(","))
+                .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+        }
+    }
+    let (total_count, unread_count) = if let Some(counts) = authoritative_counts {
+        counts
+    } else if let Some((total_count, _unread_count, _generation)) = counter_snapshot {
+        folder_counts::set_if_snapshot_matches(
+            &config,
+            &session.user_hash,
+            &name,
+            counter_snapshot,
+            total_count,
+            0,
+        )?
+    } else {
+        db::folders::get_folder(&conn, &name)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?
+            .map(|folder| (folder.total_count, folder.unread_count))
+            .unwrap_or((0, 0))
+    };
+    let (total_count, unread_count) =
+        folder_counts::current_counts(&config, &session.user_hash, &name)?
+            .unwrap_or((total_count, unread_count));
+    event_bus
+        .publish(
+            &session.user_hash,
+            MailEvent::FolderStatus {
+                folder: name.clone(),
+                total_count,
+                unread_count,
+            },
+        )
+        .await;
+    event_bus
+        .publish(
+            &session.user_hash,
+            MailEvent::FolderAllRead {
+                folder: name,
+                through_uid,
+            },
+        )
+        .await;
 
-    Ok(Json(MessageResponse { status: "read" }).into_response())
+    Ok(Json(FolderCounterResponse {
+        status: "read",
+        total_count,
+        unread_count,
+        through_uid,
+    })
+    .into_response())
 }
 
 pub async fn empty_folder(
@@ -214,21 +295,16 @@ pub async fn empty_folder(
     Extension(config): Extension<Arc<AppConfig>>,
     Extension(imap_client): Extension<Arc<dyn ImapClient>>,
     Extension(search_engine): Extension<Arc<SearchEngine>>,
+    Extension(event_bus): Extension<Arc<EventBus>>,
     Path(name): Path<String>,
 ) -> Result<Response, AppError> {
     let creds = build_creds(&session, &config)?;
-    imap_client
+    let counter_snapshot = folder_counts::snapshot(&config, &session.user_hash, &name)?;
-        .empty_folder(&creds, &name)
-        .await
-        .map_err(|e| AppError::ServiceUnavailable(format!("IMAP empty-folder failed: {e}")))?;
 
-    let conn = db::pool::open_user_db(&config.data_dir, &session.user_hash)
+    let cached_uids: Vec<u32> = {
-        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+        let conn = db::pool::open_user_db(&config.data_dir, &session.user_hash)
-    let transaction = conn
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
-        .unchecked_transaction()
+        let mut statement = conn
-        .map_err(|e| AppError::InternalError(format!("Database transaction error: {e}")))?;
-    let uids: Vec<u32> = {
-        let mut statement = transaction
             .prepare(crate::dbq!(routes_folder_mgmt::Q_003))
             .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
         let rows = statement
@@ -236,16 +312,41 @@ pub async fn empty_folder(
             .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
         rows.filter_map(Result::ok).collect()
     };
-    db::messages::delete_folder_messages(&transaction, &name)
+
+    imap_client
+        .empty_folder(&creds, &name)
+        .await
+        .map_err(|e| AppError::ServiceUnavailable(format!("IMAP empty-folder failed: {e}")))?;
+
+    let authoritative_counts = folder_counts::reconcile_after_mutation(
+        &config,
+        &session.user_hash,
+        imap_client.as_ref(),
+        &creds,
+        &name,
+        counter_snapshot,
+    )
+    .await?;
+
+    let conn = db::pool::open_user_db(&config.data_dir, &session.user_hash)
         .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
-    transaction
+    let transaction = conn
-        .execute(crate::dbq!(routes_folder_mgmt::Q_004), [&name])
+        .unchecked_transaction()
+        .map_err(|e| AppError::InternalError(format!("Database transaction error: {e}")))?;
+
+    for uid in &cached_uids {
+        db::messages::delete_message(&transaction, &name, *uid)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    }
+    db::header_sync::invalidate(&transaction)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    db::folders::invalidate_folder_freshness(&transaction, &name)
         .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
 
     if let Ok(index) = search_engine.open_user_index(&session.user_hash) {
-        for uid in uids {
+        for uid in &cached_uids {
             index
-                .delete_message_with_connection(&transaction, uid, &name)
+                .delete_message_with_connection(&transaction, *uid, &name)
                 .map_err(|e| AppError::InternalError(format!("Search outbox error: {e}")))?;
         }
     }
@@ -253,6 +354,38 @@ pub async fn empty_folder(
         .commit()
         .map_err(|e| AppError::InternalError(format!("Database commit error: {e}")))?;
 
+    let (total_count, unread_count) = if let Some(counts) = authoritative_counts {
+        counts
+    } else if counter_snapshot.is_some() {
+        folder_counts::set_if_snapshot_matches(
+            &config,
+            &session.user_hash,
+            &name,
+            counter_snapshot,
+            0,
+            0,
+        )?
+    } else {
+        folder_counts::current_counts(&config, &session.user_hash, &name)?.unwrap_or((0, 0))
+    };
+
+    let (total_count, unread_count) =
+        folder_counts::current_counts(&config, &session.user_hash, &name)?
+            .unwrap_or((total_count, unread_count));
+    event_bus
+        .publish(
+            &session.user_hash,
+            MailEvent::FolderStatus {
+                folder: name.clone(),
+                total_count,
+                unread_count,
+            },
+        )
+        .await;
+    event_bus
+        .publish(&session.user_hash, MailEvent::FolderUpdated)
+        .await;
+
     Ok(Json(MessageResponse { status: "emptied" }).into_response())
 }
 

src/routes/folders.rs

@@ -1,8 +1,9 @@
 use std::sync::Arc;
 
+use axum::extract::Query;
 use axum::response::{IntoResponse, Response};
 use axum::{Extension, Json};
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 
 use crate::auth::session::SessionState;
 use crate::config::AppConfig;
@@ -13,6 +14,8 @@ use crate::imap::client::{ImapClient, ImapCredentials};
 #[derive(Serialize)]
 struct FoldersResponse {
     folders: Vec<FolderEntry>,
+    pending_sync_count: u32,
+    pending_index_count: u32,
 }
 
 #[derive(Serialize)]
@@ -27,10 +30,23 @@ struct FolderEntry {
 
 const FOLDER_LIST_TTL_SECS: u32 = 300;
 
+fn is_noselect(flags: &str) -> bool {
+    flags
+        .split(',')
+        .any(|flag| flag.trim().eq_ignore_ascii_case("\\Noselect"))
+}
+
+#[derive(Debug, Default, Deserialize)]
+pub(crate) struct ListFoldersQuery {
+    #[serde(default)]
+    refresh: bool,
+}
+
 pub async fn list_folders(
     Extension(session): Extension<SessionState>,
     Extension(config): Extension<Arc<AppConfig>>,
     Extension(imap_client): Extension<Arc<dyn ImapClient>>,
+    Query(query): Query<ListFoldersQuery>,
 ) -> Result<Response, AppError> {
     let conn = db::pool::open_user_db(&config.data_dir, &session.user_hash)
         .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
@@ -38,16 +54,16 @@ pub async fn list_folders(
     let cache_fresh = db::folders::is_folder_cache_fresh(&conn, FOLDER_LIST_TTL_SECS)
         .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
 
-    if !cache_fresh {
+    let creds = ImapCredentials {
-        let creds = ImapCredentials {
+        host: session.imap_host.clone(),
-            host: session.imap_host.clone(),
+        port: session.imap_port,
-            port: session.imap_port,
+        tls: session.imap_tls,
-            tls: session.imap_tls,
+        tls_verify: session.imap_tls_verify,
-            tls_verify: session.imap_tls_verify,
+        email: session.email.clone(),
-            email: session.email.clone(),
+        password: session.password.clone(),
-            password: session.password.clone(),
+    };
-        };
 
+    if !cache_fresh {
         let imap_folders = imap_client
             .list_folders(&creds)
             .await
@@ -72,9 +88,84 @@ pub async fn list_folders(
             .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
     }
 
-    let cached = db::folders::get_all_folders(&conn)
+    let mut cached = db::folders::get_all_folders(&conn)
         .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
 
+    if query.refresh || !cache_fresh {
+        let names = cached
+            .iter()
+            .filter(|folder| !is_noselect(&folder.flags))
+            .map(|folder| folder.name.clone())
+            .collect::<Vec<_>>();
+        for folder in cached.iter().filter(|folder| is_noselect(&folder.flags)) {
+            db::folders::set_folder_counts(&conn, &folder.name, 0, 0)
+                .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+        }
+        let mut statuses = imap_client
+            .folder_statuses_extended(&creds, &names)
+            .await
+            .unwrap_or_default()
+            .into_iter()
+            .collect::<std::collections::HashMap<_, _>>();
+
+        for name in &names {
+            let status = if let Some(status) = statuses.remove(name) {
+                Some(status)
+            } else {
+                match imap_client.folder_status_extended(&creds, name).await {
+                    Ok(status) => Some(status),
+                    Err(error) => {
+                        tracing::debug!(folder = %name, error = %error, "Folder STATUS refresh failed; keeping cached counters");
+                        None
+                    }
+                }
+            };
+            let Some(status) = status else { continue };
+            let cached_folder = cached
+                .iter()
+                .find(|folder| folder.name.as_str() == name.as_str());
+            if let Some(cached_folder) = cached_folder
+                && cached_folder.uid_validity != 0
+                && status.uid_validity != 0
+                && cached_folder.uid_validity != status.uid_validity
+            {
+                db::folders::invalidate_folder_freshness(&conn, name)
+                    .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+            }
+
+            if let Some(cached_folder) = cached_folder {
+                let applied = db::folders::set_folder_counts_if_unchanged(
+                    &conn,
+                    name,
+                    cached_folder.counter_generation,
+                    status.exists,
+                    status.unseen,
+                )
+                .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+                if !applied {
+                    tracing::debug!(folder = %name, "Skipped stale folder STATUS counters");
+                }
+            } else {
+                db::folders::set_folder_counts(&conn, name, status.exists, status.unseen)
+                    .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+            }
+        }
+        cached = db::folders::get_all_folders(&conn)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    }
+
+    let pending_sync_count = db::folders::pending_message_sync_count(&conn)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?;
+    let account_deep_index = db::display_preferences::get_preferences(&conn)
+        .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?
+        .deep_index;
+    let pending_index_count = if config.search.deep_index || account_deep_index {
+        db::messages::count_unindexed_messages(&conn)
+            .map_err(|e| AppError::InternalError(format!("Database error: {e}")))?
+    } else {
+        0
+    };
+
     let folders: Vec<FolderEntry> = cached
         .into_iter()
         .map(|f| {
@@ -94,5 +185,10 @@ pub async fn list_folders(
         })
         .collect();
 
-    Ok(Json(FoldersResponse { folders }).into_response())
+    Ok(Json(FoldersResponse {
+        folders,
+        pending_sync_count,
+        pending_index_count,
+    })
+    .into_response())
 }

src/routes/mod.rs

@@ -6,6 +6,7 @@ pub mod contacts;
 pub mod diagnostics;
 pub mod display_preferences;
 pub mod drafts;
+pub mod folder_counts;
 pub mod folder_mgmt;
 pub mod folder_preferences;
 pub mod folders;
@@ -22,6 +23,7 @@ pub mod send;
 pub mod settings;
 pub mod sieve;
 pub mod special_folders;
+pub mod system_diagnostics;
 pub mod tags;
 pub mod trusted_senders;
 pub mod unsubscribe;
@@ -32,7 +34,7 @@ use std::time::Duration;
 
 use axum::body::Body;
 use axum::extract::{ConnectInfo, DefaultBodyLimit};
-use axum::http::{HeaderValue, Request};
+use axum::http::{HeaderValue, Request, header};
 use axum::response::Response;
 use axum::routing::{delete, get, patch, post, put};
 use axum::{Extension, Router, middleware};
@@ -104,29 +106,70 @@ impl KeyExtractor for ProxyAwareIpExtractor {
     }
 }
 
+fn response_content_type_is(response: &Response, expected: &str) -> bool {
+    response
+        .headers()
+        .get(header::CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .and_then(|value| value.split(';').next())
+        .is_some_and(|value| value.trim().eq_ignore_ascii_case(expected))
+}
+
 async fn add_security_headers(request: Request<Body>, next: middleware::Next) -> Response {
+    let request_path = request.uri().path().to_owned();
+    let is_api =
+        request_path == "/api" || request_path.ends_with("/api") || request_path.contains("/api/");
     let mut response = next.run(request).await;
+    let is_html = response_content_type_is(&response, "text/html")
+        || response_content_type_is(&response, "application/xhtml+xml");
+    let is_css = response_content_type_is(&response, "text/css");
     let headers = response.headers_mut();
+
     headers.insert(
         "x-content-type-options",
         HeaderValue::from_static("nosniff"),
     );
-    headers.insert("x-frame-options", HeaderValue::from_static("DENY"));
+
-    headers.insert("referrer-policy", HeaderValue::from_static("no-referrer"));
+    if is_api {
-    headers.insert(
+        headers.insert(header::CACHE_CONTROL, HeaderValue::from_static("no-store"));
-        "permissions-policy",
+        headers.insert(
-        HeaderValue::from_static("camera=(), microphone=(), geolocation=()"),
+            "cross-origin-resource-policy",
-    );
+            HeaderValue::from_static("same-origin"),
-    headers.insert(
+        );
-        "cross-origin-opener-policy",
+        headers.insert("x-frame-options", HeaderValue::from_static("DENY"));
-        HeaderValue::from_static("same-origin"),
+        headers.insert(
-    );
+            "content-security-policy",
-    headers.insert(
+            HeaderValue::from_static("frame-ancestors 'none'"),
-        "content-security-policy",
+        );
-        HeaderValue::from_static(
+    } else if is_html || is_css {
-            "default-src 'self'; base-uri 'self'; object-src 'none'; frame-ancestors 'none'; form-action 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob: http: https:; font-src 'self' data:; connect-src 'self' ws: wss:",
+        headers.insert("referrer-policy", HeaderValue::from_static("no-referrer"));
-        ),
+    }
-    );
+
+    if request_path.contains("/assets/") || request_path.ends_with("/favicon.svg") {
+        headers.insert(
+            "cross-origin-resource-policy",
+            HeaderValue::from_static("same-origin"),
+        );
+    }
+
+    if is_html {
+        headers.insert("x-frame-options", HeaderValue::from_static("DENY"));
+        headers.insert(
+            "permissions-policy",
+            HeaderValue::from_static("camera=(), microphone=(), geolocation=()"),
+        );
+        headers.insert(
+            "cross-origin-opener-policy",
+            HeaderValue::from_static("same-origin"),
+        );
+        headers.insert(
+            "content-security-policy",
+            HeaderValue::from_static(
+                "default-src 'self'; base-uri 'self'; object-src 'none'; frame-ancestors 'none'; form-action 'self'; script-src 'self'; script-src-attr 'none'; style-src 'self'; style-src-attr 'unsafe-inline'; img-src 'self' data: blob: http: https:; font-src 'self' data:; connect-src 'self' ws: wss:; frame-src 'self' blob:",
+            ),
+        );
+    }
+
     response
 }
 
@@ -176,6 +219,8 @@ pub fn create_router_with_storage(config: Arc<AppConfig>, services: RouterServic
         event_bus,
         idle_manager,
     } = services;
+    let system_diagnostics_telemetry =
+        Arc::new(system_diagnostics::SystemDiagnosticsTelemetry::new());
     let governor_conf = GovernorConfigBuilder::default()
         .key_extractor(ProxyAwareIpExtractor {
             trusted_proxies: config.parsed_trusted_proxies(),
@@ -200,6 +245,7 @@ pub fn create_router_with_storage(config: Arc<AppConfig>, services: RouterServic
 
     let protected_auth = Router::new()
         .route("/session", get(auth::get_session))
+        .route("/session-policy", get(auth::session_policy))
         .route("/sessions", get(auth::list_active_sessions))
         .route("/sessions/revoke-others", post(auth::revoke_other_sessions))
         .route("/sessions/{id}", delete(auth::revoke_active_session))
@@ -532,13 +578,27 @@ pub fn create_router_with_storage(config: Arc<AppConfig>, services: RouterServic
 
     let ws_route = Router::new().route("/ws", get(crate::realtime::ws::ws_handler));
 
-    let api_router = Router::new()
+    let mut api_router = Router::new()
         .route("/health", get(health::health_check))
         .route("/ready", get(health::readiness_check))
         .nest("/auth", auth_router)
         .merge(ws_route)
-        .merge(protected_data)
+        .merge(protected_data);
-        .fallback(|| async { axum::http::StatusCode::NOT_FOUND });
+
+    if config.diagnostics_endpoint.enabled {
+        let diagnostics_path = config
+            .diagnostics_endpoint
+            .path
+            .trim()
+            .strip_prefix("/api")
+            .unwrap_or(config.diagnostics_endpoint.path.trim());
+        api_router = api_router.route(
+            diagnostics_path,
+            get(system_diagnostics::system_diagnostics),
+        );
+    }
+
+    let api_router = api_router.fallback(|| async { axum::http::StatusCode::NOT_FOUND });
 
     let inner = Router::new()
         .nest("/api", api_router)
@@ -555,6 +615,24 @@ pub fn create_router_with_storage(config: Arc<AppConfig>, services: RouterServic
         }
     };
 
+    let router = if config.diagnostics_endpoint.enabled {
+        let system_diagnostics_dependencies =
+            Arc::new(system_diagnostics::SystemDiagnosticsDependencies::new(
+                config.clone(),
+                store.clone(),
+                search_engine.clone(),
+                storage.clone(),
+                idle_manager.clone(),
+                system_diagnostics_telemetry.clone(),
+            ));
+        router
+            .layer(middleware::from_fn(system_diagnostics::observe_requests))
+            .layer(Extension(system_diagnostics_dependencies))
+            .layer(Extension(system_diagnostics_telemetry))
+    } else {
+        router
+    };
+
     let router = router
         .layer(Extension(idle_manager))
         .layer(Extension(event_bus))

src/routes/pgp.rs

@@ -378,10 +378,6 @@ pub async fn export_key(
         HeaderValue::from_static("application/pgp-keys; charset=utf-8"),
     );
     headers.insert("cache-control", HeaderValue::from_static("no-store"));
-    headers.insert(
-        "x-content-type-options",
-        HeaderValue::from_static("nosniff"),
-    );
     headers.insert(
         "content-disposition",
         HeaderValue::from_str(&format!("attachment; filename=\"{filename}\""))

src/routes/system_diagnostics.rs

@@ -0,0 +1,896 @@
+use std::collections::{HashMap, VecDeque};
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+
+use axum::body::Body;
+use axum::extract::ConnectInfo;
+use axum::http::{HeaderMap, HeaderValue, Request, StatusCode, header};
+use axum::middleware;
+use axum::response::{IntoResponse, Response};
+use axum::{Extension, Json};
+use base64::Engine as _;
+use base64::engine::general_purpose::STANDARD;
+use serde::Serialize;
+use serde_json::{Value, json};
+use sha2::{Digest, Sha256};
+
+use crate::auth::session::SessionStore;
+use crate::config::{AppConfig, TrustedProxy};
+use crate::db;
+use crate::realtime::idle::IdleManager;
+use crate::search::engine::SearchEngine;
+use crate::storage::BlobStorage;
+
+const MAX_SECURITY_EVENTS: usize = 4096;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize)]
+#[serde(rename_all = "snake_case")]
+enum SecurityEventKind {
+    LoginRejected,
+    RateLimited,
+    Forbidden,
+    ServerError,
+    DiagnosticsDenied,
+}
+
+#[derive(Debug, Clone)]
+struct SecurityEvent {
+    at_unix: u64,
+    kind: SecurityEventKind,
+    source_ip: IpAddr,
+    path: String,
+}
+
+pub struct SystemDiagnosticsTelemetry {
+    started_at_unix: u64,
+    started: Instant,
+    total_requests: AtomicU64,
+    client_errors: AtomicU64,
+    server_errors: AtomicU64,
+    login_attempts: AtomicU64,
+    events: Mutex<VecDeque<SecurityEvent>>,
+}
+
+pub struct SystemDiagnosticsDependencies {
+    config: Arc<AppConfig>,
+    store: Arc<SessionStore>,
+    search: Arc<SearchEngine>,
+    storage: Arc<dyn BlobStorage>,
+    idle_manager: Arc<IdleManager>,
+    telemetry: Arc<SystemDiagnosticsTelemetry>,
+}
+
+impl SystemDiagnosticsDependencies {
+    pub fn new(
+        config: Arc<AppConfig>,
+        store: Arc<SessionStore>,
+        search: Arc<SearchEngine>,
+        storage: Arc<dyn BlobStorage>,
+        idle_manager: Arc<IdleManager>,
+        telemetry: Arc<SystemDiagnosticsTelemetry>,
+    ) -> Self {
+        Self {
+            config,
+            store,
+            search,
+            storage,
+            idle_manager,
+            telemetry,
+        }
+    }
+}
+
+impl SystemDiagnosticsTelemetry {
+    pub fn new() -> Self {
+        Self {
+            started_at_unix: now_unix(),
+            started: Instant::now(),
+            total_requests: AtomicU64::new(0),
+            client_errors: AtomicU64::new(0),
+            server_errors: AtomicU64::new(0),
+            login_attempts: AtomicU64::new(0),
+            events: Mutex::new(VecDeque::with_capacity(MAX_SECURITY_EVENTS)),
+        }
+    }
+
+    fn record_event(&self, kind: SecurityEventKind, source_ip: IpAddr, path: &str) {
+        let mut events = self
+            .events
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        if events.len() >= MAX_SECURITY_EVENTS {
+            events.pop_front();
+        }
+        events.push_back(SecurityEvent {
+            at_unix: now_unix(),
+            kind,
+            source_ip,
+            path: path.chars().take(256).collect(),
+        });
+    }
+
+    fn security_snapshot(&self, window_secs: u64) -> Value {
+        let now = now_unix();
+        let cutoff = now.saturating_sub(window_secs);
+        let events = self
+            .events
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        let mut by_kind: HashMap<SecurityEventKind, u64> = HashMap::new();
+        let mut by_ip: HashMap<IpAddr, u64> = HashMap::new();
+        let mut recent = Vec::new();
+        for event in events.iter().filter(|event| event.at_unix >= cutoff) {
+            *by_kind.entry(event.kind).or_default() += 1;
+            *by_ip.entry(event.source_ip).or_default() += 1;
+        }
+        for event in events
+            .iter()
+            .rev()
+            .filter(|event| event.at_unix >= cutoff)
+            .take(50)
+        {
+            recent.push(json!({
+                "timestampUnix": event.at_unix,
+                "kind": event.kind,
+                "sourceIp": event.source_ip.to_string(),
+                "path": event.path,
+            }));
+        }
+        let mut top_sources: Vec<(IpAddr, u64)> = by_ip.into_iter().collect();
+        top_sources.sort_by_key(|source| std::cmp::Reverse(source.1));
+        top_sources.truncate(20);
+
+        let login_rejected = *by_kind.get(&SecurityEventKind::LoginRejected).unwrap_or(&0);
+        let rate_limited = *by_kind.get(&SecurityEventKind::RateLimited).unwrap_or(&0);
+        let forbidden = *by_kind.get(&SecurityEventKind::Forbidden).unwrap_or(&0);
+        let server_errors = *by_kind.get(&SecurityEventKind::ServerError).unwrap_or(&0);
+        let diagnostics_denied = *by_kind
+            .get(&SecurityEventKind::DiagnosticsDenied)
+            .unwrap_or(&0);
+
+        let brute_force_signal = login_rejected >= 10 || rate_limited >= 3;
+        let diagnostics_attack_signal = diagnostics_denied >= 5;
+        json!({
+            "windowSeconds": window_secs,
+            "loginRejected": login_rejected,
+            "rateLimited": rate_limited,
+            "forbidden": forbidden,
+            "serverErrors": server_errors,
+            "diagnosticsDenied": diagnostics_denied,
+            "bruteForceSignal": brute_force_signal,
+            "diagnosticsAttackSignal": diagnostics_attack_signal,
+            "securityAlert": brute_force_signal || diagnostics_attack_signal,
+            "topSources": top_sources.into_iter().map(|(ip, count)| json!({
+                "ip": ip.to_string(), "events": count
+            })).collect::<Vec<_>>(),
+            "recentEvents": recent,
+            "bufferCapacity": MAX_SECURITY_EVENTS,
+            "bufferUsed": events.len(),
+        })
+    }
+}
+
+impl Default for SystemDiagnosticsTelemetry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+fn now_unix() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
+}
+
+fn trusted_contains(trusted: &[TrustedProxy], ip: &IpAddr) -> bool {
+    trusted.iter().any(|entry| entry.contains(ip))
+}
+
+fn effective_client_ip(config: &AppConfig, headers: &HeaderMap, peer_ip: IpAddr) -> IpAddr {
+    let trusted = config.parsed_trusted_proxies();
+    if !trusted_contains(&trusted, &peer_ip) {
+        return peer_ip;
+    }
+
+    let mut current = peer_ip;
+    for value in headers.get_all("x-forwarded-for").iter().rev() {
+        let Ok(value) = value.to_str() else {
+            return current;
+        };
+        for entry in value.split(',').rev() {
+            if !trusted_contains(&trusted, &current) {
+                return current;
+            }
+            let Ok(parsed) = entry.trim().parse::<IpAddr>() else {
+                return current;
+            };
+            current = parsed;
+        }
+    }
+    current
+}
+
+fn diagnostics_client_ip(
+    config: &AppConfig,
+    headers: &HeaderMap,
+    peer_ip: IpAddr,
+) -> Result<IpAddr, &'static str> {
+    let has_xff = headers.contains_key("x-forwarded-for");
+    let has_other_forwarding =
+        headers.contains_key("forwarded") || headers.contains_key("x-real-ip");
+    if !has_xff && !has_other_forwarding {
+        return Ok(peer_ip);
+    }
+
+    let trusted = config.parsed_trusted_proxies();
+    if !trusted_contains(&trusted, &peer_ip) {
+        return Err("proxy headers received from an untrusted peer");
+    }
+    if !has_xff {
+        return Err("diagnostics requires X-Forwarded-For when accessed through a trusted proxy");
+    }
+
+    let mut current = peer_ip;
+    let mut saw_forwarded_address = false;
+    for value in headers.get_all("x-forwarded-for").iter().rev() {
+        let value = value
+            .to_str()
+            .map_err(|_| "invalid X-Forwarded-For header encoding")?;
+        for entry in value.split(',').rev() {
+            if !trusted_contains(&trusted, &current) {
+                return Ok(current);
+            }
+            current = entry
+                .trim()
+                .parse::<IpAddr>()
+                .map_err(|_| "invalid X-Forwarded-For address")?;
+            saw_forwarded_address = true;
+        }
+    }
+    if !saw_forwarded_address {
+        return Err("empty X-Forwarded-For header");
+    }
+    Ok(current)
+}
+
+pub async fn observe_requests(request: Request<Body>, next: middleware::Next) -> Response {
+    let telemetry = request
+        .extensions()
+        .get::<Arc<SystemDiagnosticsTelemetry>>()
+        .cloned();
+    let config = request.extensions().get::<Arc<AppConfig>>().cloned();
+    let path = request.uri().path().to_string();
+    let peer_ip = request
+        .extensions()
+        .get::<ConnectInfo<SocketAddr>>()
+        .map(|value| value.0.ip())
+        .unwrap_or(IpAddr::V4(Ipv4Addr::LOCALHOST));
+    let source_ip = config
+        .as_deref()
+        .map(|cfg| effective_client_ip(cfg, request.headers(), peer_ip))
+        .unwrap_or(peer_ip);
+    let is_login = path.ends_with("/api/auth/login");
+
+    if let Some(telemetry) = telemetry.as_ref() {
+        telemetry.total_requests.fetch_add(1, Ordering::Relaxed);
+        if is_login {
+            telemetry.login_attempts.fetch_add(1, Ordering::Relaxed);
+        }
+    }
+
+    let response = next.run(request).await;
+    if let Some(telemetry) = telemetry.as_ref() {
+        let status = response.status();
+        if status.is_client_error() {
+            telemetry.client_errors.fetch_add(1, Ordering::Relaxed);
+        }
+        if status.is_server_error() {
+            telemetry.server_errors.fetch_add(1, Ordering::Relaxed);
+            telemetry.record_event(SecurityEventKind::ServerError, source_ip, &path);
+        }
+        if status == StatusCode::TOO_MANY_REQUESTS {
+            telemetry.record_event(SecurityEventKind::RateLimited, source_ip, &path);
+            tracing::warn!(source_ip = %source_ip, path = %path, "request rate limited");
+        }
+        if status == StatusCode::FORBIDDEN {
+            telemetry.record_event(SecurityEventKind::Forbidden, source_ip, &path);
+        }
+        if is_login && matches!(status, StatusCode::UNAUTHORIZED | StatusCode::FORBIDDEN) {
+            telemetry.record_event(SecurityEventKind::LoginRejected, source_ip, &path);
+            tracing::warn!(source_ip = %source_ip, status = %status, "login rejected");
+        }
+    }
+    response
+}
+
+fn constant_time_secret_eq(expected: &str, supplied: &str) -> bool {
+    let expected = Sha256::digest(expected.as_bytes());
+    let supplied = Sha256::digest(supplied.as_bytes());
+    expected
+        .iter()
+        .zip(supplied.iter())
+        .fold(0u8, |diff, (left, right)| diff | (left ^ right))
+        == 0
+}
+
+fn bearer_token(headers: &HeaderMap) -> Option<&str> {
+    let authorization = headers
+        .get(header::AUTHORIZATION)
+        .and_then(|value| value.to_str().ok())
+        .and_then(|value| {
+            let mut parts = value.split_whitespace();
+            let scheme = parts.next()?;
+            let credentials = parts.next()?;
+            if parts.next().is_some() {
+                return None;
+            }
+            scheme.eq_ignore_ascii_case("bearer").then_some(credentials)
+        });
+    authorization.or_else(|| {
+        headers
+            .get("x-rustbox-diagnostics-token")
+            .and_then(|value| value.to_str().ok())
+            .map(str::trim)
+    })
+}
+
+fn basic_credentials(headers: &HeaderMap) -> Option<(String, String)> {
+    let raw = headers.get(header::AUTHORIZATION)?.to_str().ok()?;
+    let mut parts = raw.split_whitespace();
+    let scheme = parts.next()?;
+    let encoded = parts.next()?;
+    if parts.next().is_some() || !scheme.eq_ignore_ascii_case("basic") {
+        return None;
+    }
+    let decoded = STANDARD.decode(encoded).ok()?;
+    let decoded = String::from_utf8(decoded).ok()?;
+    let (username, password) = decoded.split_once(':')?;
+    Some((username.to_string(), password.to_string()))
+}
+
+fn harden_diagnostics_response(mut response: Response) -> Response {
+    let headers = response.headers_mut();
+    headers.insert(header::CACHE_CONTROL, HeaderValue::from_static("no-store"));
+    headers.insert("pragma", HeaderValue::from_static("no-cache"));
+    headers.insert(
+        "x-content-type-options",
+        HeaderValue::from_static("nosniff"),
+    );
+    headers.insert(
+        "cross-origin-resource-policy",
+        HeaderValue::from_static("same-origin"),
+    );
+    response
+}
+
+fn unauthorized(auth_mode: &str) -> Response {
+    let challenge = if auth_mode.eq_ignore_ascii_case("basic") {
+        "Basic realm=\"RustBox diagnostics\", charset=\"UTF-8\""
+    } else {
+        "Bearer realm=\"RustBox diagnostics\""
+    };
+    let mut response = (
+        StatusCode::UNAUTHORIZED,
+        Json(json!({"error": "diagnostics authentication required"})),
+    )
+        .into_response();
+    response.headers_mut().insert(
+        header::WWW_AUTHENTICATE,
+        HeaderValue::from_str(challenge).unwrap_or_else(|_| HeaderValue::from_static("Bearer")),
+    );
+    harden_diagnostics_response(response)
+}
+
+fn forbidden() -> Response {
+    harden_diagnostics_response(
+        (
+            StatusCode::FORBIDDEN,
+            Json(json!({"error": "diagnostics endpoint is not available from this network"})),
+        )
+            .into_response(),
+    )
+}
+
+fn sanitize_url(raw: Option<&str>) -> Option<String> {
+    let raw = raw?.trim();
+    if raw.is_empty() {
+        return None;
+    }
+    if let Ok(url) = url::Url::parse(raw) {
+        if url.scheme() == "sqlite" {
+            return Some(format!("sqlite:{}", url.path()));
+        }
+        let host = url.host_str().unwrap_or("<unknown-host>");
+        let port = url
+            .port()
+            .map(|value| format!(":{value}"))
+            .unwrap_or_default();
+        let path = if url.path() == "/" { "" } else { url.path() };
+        return Some(format!("{}://{}{}{}", url.scheme(), host, port, path));
+    }
+    Some("<configured; redacted>".to_string())
+}
+
+fn process_snapshot() -> Value {
+    // Keep this intentionally limited to portable, process-local information.
+    // Rust std does not expose cross-platform RSS/thread/FD metrics, and the
+    // diagnostics endpoint must not depend on host-specific /proc probes.
+    json!({
+        "pid": std::process::id(),
+    })
+}
+
+fn sanitized_config(config: &AppConfig) -> Value {
+    json!({
+        "environment": config.environment,
+        "pathsAndLogging": {
+            "dataDir": config.data_dir,
+            "logDir": config.log_dir,
+            "logLevel": config.log_level,
+        },
+        "ui": {
+            "defaultTheme": config.default_theme,
+            "defaultInterfaceSkin": config.default_interface_skin,
+        },
+        "listen": {"host": config.host, "port": config.port, "basePath": config.base_path},
+        "mail": {
+            "imapHost": config.imap_host,
+            "imapPort": config.imap_port,
+            "smtpHost": config.smtp_host,
+            "smtpPort": config.smtp_port,
+            "tlsEnabled": config.tls_enabled,
+            "tlsVerifyOverride": config.tls_verify,
+            "sieveEnabled": config.sieve_enabled,
+            "sieveHost": config.sieve_host,
+            "sievePort": config.sieve_port,
+            "sieveTlsMode": config.sieve_tls_mode,
+            "sieveAllowInsecureAuth": config.sieve_allow_insecure_auth,
+            "sieveTimeoutSecs": config.sieve_timeout_secs,
+        },
+        "limits": {
+            "maxAttachmentSizeMiB": config.max_attachment_size_mb,
+            "maxMessageSizeMiB": config.max_message_size_mb,
+            "sessionTimeoutHours": config.session_timeout_hours,
+            "rememberMeEnabled": config.remember_me_enabled,
+            "rememberMeDays": config.remember_me_days,
+        },
+        "database": {
+            "backend": config.database_backend,
+            "url": sanitize_url(config.database_url.as_deref()),
+        },
+        "sessions": {
+            "backend": config.session_backend,
+            "redisUrl": sanitize_url(config.redis_url.as_deref()),
+            "redisSentinelNodes": config.redis_sentinel_nodes.iter().map(|value| sanitize_url(Some(value)).unwrap_or_else(|| value.clone())).collect::<Vec<_>>(),
+            "redisSentinelMaster": config.redis_sentinel_master,
+            "redisPasswordConfigured": config.redis_password.as_deref().is_some_and(|value| !value.is_empty()),
+            "redisSentinelPasswordConfigured": config.redis_sentinel_password.as_deref().is_some_and(|value| !value.is_empty()),
+            "sessionEncryptionKeyConfigured": config.session_encryption_key.as_deref().is_some_and(|value| !value.is_empty()),
+        },
+        "clusterMode": config.cluster_mode,
+        "storage": {
+            "backend": config.storage.backend,
+            "path": config.storage.path,
+            "shared": config.storage.shared,
+            "bucket": config.storage.bucket,
+            "region": config.storage.region,
+            "endpoint": sanitize_url(config.storage.endpoint.as_deref()),
+            "prefix": config.storage.prefix,
+            "pathStyle": config.storage.path_style,
+            "allowHttp": config.storage.allow_http,
+            "accessKeyConfigured": config.storage.access_key_id.as_deref().is_some_and(|value| !value.is_empty()),
+            "secretKeyConfigured": config.storage.secret_access_key.as_deref().is_some_and(|value| !value.is_empty()),
+            "sessionTokenConfigured": config.storage.session_token.as_deref().is_some_and(|value| !value.is_empty()),
+            "requestTimeoutSecs": config.storage.request_timeout_secs,
+            "connectTimeoutSecs": config.storage.connect_timeout_secs,
+            "maxRetries": config.storage.max_retries,
+            "retryTimeoutSecs": config.storage.retry_timeout_secs,
+            "serverSideEncryption": config.storage.server_side_encryption,
+            "kmsKeyConfigured": config.storage.kms_key_id.as_deref().is_some_and(|value| !value.is_empty()),
+        },
+        "search": {
+            "backend": config.search.backend,
+            "path": config.search.path,
+            "urls": config.search.urls.iter().map(|value| sanitize_url(Some(value)).unwrap_or_else(|| "<invalid url>".to_string())).collect::<Vec<_>>(),
+            "indexPrefix": config.search.index_prefix,
+            "usernameConfigured": config.search.username.as_deref().is_some_and(|value| !value.is_empty()),
+            "passwordConfigured": config.search.password.as_deref().is_some_and(|value| !value.is_empty()),
+            "required": config.search.required,
+            "allowInsecureHttp": config.search.allow_insecure_http,
+            "requestTimeoutSecs": config.search.request_timeout_secs,
+            "deepIndex": config.search.deep_index,
+            "workerIntervalSecs": config.search.worker_interval_secs,
+            "workerBatchSize": config.search.worker_batch_size,
+            "workerMaxAttempts": config.search.worker_max_attempts,
+        },
+        "sync": {
+            "intervalSecs": config.sync.interval_secs,
+            "deepIndexBatchSize": config.sync.deep_index_batch_size,
+        },
+        "features": {
+            "userDiagnostics": config.diagnostics_enabled,
+            "about": config.about_enabled,
+            "pgp": config.pgp_enabled,
+            "securityHeaders": config.security_headers_enabled,
+        },
+        "pgp": {
+            "enabled": config.pgp_enabled,
+            "wkdEnabled": config.pgp_wkd_enabled,
+            "hkpEnabled": config.pgp_hkp_enabled,
+            "hkpUrl": sanitize_url(Some(&config.pgp_hkp_url)),
+            "networkTimeoutSecs": config.pgp_network_timeout_secs,
+            "maxKeyBytes": config.pgp_max_key_bytes,
+            "allowPrivateExport": config.pgp_allow_private_export,
+        },
+        "specialFolders": {
+            "sent": config.default_sent_folder,
+            "drafts": config.default_drafts_folder,
+            "trash": config.default_trash_folder,
+            "junk": config.default_junk_folder,
+            "archive": config.default_archive_folder,
+        },
+        "outgoingHeaders": {
+            "count": config.outgoing_headers.len(),
+            "names": config.outgoing_headers.iter().filter_map(|entry| entry.split_once(':').map(|(name, _)| name.trim().to_string())).collect::<Vec<_>>(),
+        },
+        "trustedProxies": config.trusted_proxies,
+        "diagnosticsEndpoint": {
+            "enabled": config.diagnostics_endpoint.enabled,
+            "path": config.diagnostics_endpoint.path,
+            "allowedNetworks": config.diagnostics_endpoint.allowed_networks,
+            "auth": config.diagnostics_endpoint.auth,
+            "credentialConfigured": if config.diagnostics_endpoint.auth.eq_ignore_ascii_case("basic") {
+                config.diagnostics_endpoint.basic_username.as_deref().is_some_and(|value| !value.is_empty())
+                    && config.diagnostics_endpoint.basic_password.as_deref().is_some_and(|value| !value.is_empty())
+            } else {
+                config.diagnostics_endpoint.token.as_deref().is_some_and(|value| !value.is_empty())
+            },
+            "includeUserIdentifiers": config.diagnostics_endpoint.include_user_identifiers,
+            "probeTimeoutSecs": config.diagnostics_endpoint.probe_timeout_secs,
+            "securityWindowSecs": config.diagnostics_endpoint.security_window_secs,
+        }
+    })
+}
+
+fn configuration_checks(config: &AppConfig) -> Vec<Value> {
+    let mut checks = Vec::new();
+    if config.environment.eq_ignore_ascii_case("production") && !config.security_headers_enabled {
+        checks.push(json!({"severity":"warning","code":"security_headers_disabled","message":"Browser security headers are disabled in production."}));
+    }
+    if config.search.allow_insecure_http {
+        checks.push(json!({"severity":"warning","code":"opensearch_http_allowed","message":"OpenSearch permits plain HTTP."}));
+    }
+    if config.storage.allow_http {
+        checks.push(json!({"severity":"warning","code":"storage_http_allowed","message":"S3-compatible storage permits plain HTTP."}));
+    }
+    if config
+        .diagnostics_endpoint
+        .allowed_networks
+        .iter()
+        .any(|network| matches!(network.trim(), "0.0.0.0/0" | "::/0"))
+    {
+        checks.push(json!({"severity":"warning","code":"diagnostics_allowlist_global","message":"Diagnostics allowlist contains a global network; restrict it at the application and firewall/reverse-proxy layers."}));
+    }
+    if config
+        .diagnostics_endpoint
+        .auth
+        .eq_ignore_ascii_case("basic")
+    {
+        checks.push(json!({"severity":"info","code":"diagnostics_basic_auth","message":"Diagnostics uses Basic Auth; transport must be protected by HTTPS/TLS at RustBox or its trusted reverse proxy."}));
+    }
+    if config.diagnostics_endpoint.include_user_identifiers {
+        checks.push(json!({"severity":"info","code":"diagnostics_user_identifiers","message":"Diagnostics may expose authenticated user e-mail addresses and stable user hashes to authorized operators."}));
+    }
+    if config.search.deep_index {
+        checks.push(json!({"severity":"info","code":"deep_index_enabled","message":"Server-wide deep index is enabled; full message bodies may be fetched and stored/indexed automatically."}));
+    }
+    if config.tls_verify == Some(false) {
+        checks.push(json!({"severity":"warning","code":"tls_verification_disabled","message":"TLS certificate verification is globally disabled for configured mail connections."}));
+    }
+    checks
+}
+
+async fn timed_probe<F, T>(timeout: Duration, future: F) -> (Result<T, String>, u128)
+where
+    F: std::future::Future<Output = Result<T, String>>,
+{
+    let started = Instant::now();
+    let result = match tokio::time::timeout(timeout, future).await {
+        Ok(result) => result,
+        Err(_) => Err(format!("probe timed out after {} ms", timeout.as_millis())),
+    };
+    (result, started.elapsed().as_millis())
+}
+
+pub async fn system_diagnostics(
+    ConnectInfo(peer): ConnectInfo<SocketAddr>,
+    headers: HeaderMap,
+    Extension(dependencies): Extension<Arc<SystemDiagnosticsDependencies>>,
+) -> Response {
+    let config = dependencies.config.as_ref();
+    let store = dependencies.store.as_ref();
+    let search = dependencies.search.as_ref();
+    let storage = dependencies.storage.as_ref();
+    let idle_manager = dependencies.idle_manager.as_ref();
+    let telemetry = dependencies.telemetry.as_ref();
+    let source_ip = match diagnostics_client_ip(config, &headers, peer.ip()) {
+        Ok(source_ip) => source_ip,
+        Err(_) => {
+            telemetry.record_event(
+                SecurityEventKind::DiagnosticsDenied,
+                peer.ip(),
+                &config.diagnostics_endpoint.path,
+            );
+            tracing::warn!(peer_ip = %peer.ip(), "administrator diagnostics proxy/source validation denied");
+            return forbidden();
+        }
+    };
+    let allowed = config
+        .parsed_diagnostics_allowed_networks()
+        .map(|networks| networks.iter().any(|network| network.contains(&source_ip)))
+        .unwrap_or(false);
+    if !allowed {
+        telemetry.record_event(
+            SecurityEventKind::DiagnosticsDenied,
+            source_ip,
+            &config.diagnostics_endpoint.path,
+        );
+        tracing::warn!(source_ip = %source_ip, "administrator diagnostics denied by network allowlist");
+        return forbidden();
+    }
+
+    let authenticated = if config
+        .diagnostics_endpoint
+        .auth
+        .eq_ignore_ascii_case("basic")
+    {
+        match (
+            config.diagnostics_endpoint.basic_username.as_deref(),
+            config.diagnostics_endpoint.basic_password.as_deref(),
+            basic_credentials(&headers),
+        ) {
+            (Some(expected_user), Some(expected_password), Some((user, password))) => {
+                constant_time_secret_eq(expected_user, &user)
+                    && constant_time_secret_eq(expected_password, &password)
+            }
+            _ => false,
+        }
+    } else {
+        match (
+            config.diagnostics_endpoint.token.as_deref(),
+            bearer_token(&headers),
+        ) {
+            (Some(expected), Some(supplied)) => constant_time_secret_eq(expected, supplied),
+            _ => false,
+        }
+    };
+    if !authenticated {
+        telemetry.record_event(
+            SecurityEventKind::DiagnosticsDenied,
+            source_ip,
+            &config.diagnostics_endpoint.path,
+        );
+        tracing::warn!(source_ip = %source_ip, auth_mode = %config.diagnostics_endpoint.auth, "administrator diagnostics authentication rejected");
+        return unauthorized(&config.diagnostics_endpoint.auth);
+    }
+
+    let timeout = Duration::from_secs(config.diagnostics_endpoint.probe_timeout_secs);
+    let db_future = async { Ok::<_, String>(db::pool::diagnostics().await) };
+    let storage_future = async { storage.health().await };
+    let search_future = async { search.diagnostics().await };
+    let sessions_future = store.persistence_diagnostics();
+    let (db_probe, storage_probe, search_probe, session_probe) = tokio::join!(
+        timed_probe(timeout, db_future),
+        timed_probe(timeout, storage_future),
+        timed_probe(timeout, search_future),
+        timed_probe(timeout, sessions_future),
+    );
+
+    let db_diag = db_probe
+        .0
+        .unwrap_or_else(|error| db::pool::DatabaseDiagnostics {
+            backend: config.database_backend.clone(),
+            status: "error".to_string(),
+            latency_ms: db_probe.1,
+            pool_size: None,
+            idle_connections: None,
+            database_bytes: None,
+            engine_version: None,
+            account_count: None,
+            schema_version_min: None,
+            schema_version_max: None,
+            schema_aligned: None,
+            expected_schema_version: db::pool::latest_schema_version(),
+            error: Some(error),
+        });
+    let storage_status = match storage_probe.0 {
+        Ok(()) => json!({"status":"ok","latencyMs":storage_probe.1}),
+        Err(error) => json!({"status":"error","latencyMs":storage_probe.1,"error":error}),
+    };
+    let search_status = match search_probe.0 {
+        Ok(details) => {
+            let detail_status = details
+                .get("status")
+                .and_then(Value::as_str)
+                .unwrap_or("ok");
+            let status = if detail_status == "degraded" {
+                "degraded"
+            } else {
+                "ok"
+            };
+            json!({"status":status,"latencyMs":search_probe.1,"backend":search.backend_name(),"required":config.search.required,"details":details})
+        }
+        Err(error) => {
+            json!({"status": if config.search.required {"error"} else {"degraded"},"latencyMs":search_probe.1,"backend":search.backend_name(),"required":config.search.required,"error":error})
+        }
+    };
+    let session_status = match session_probe.0 {
+        Ok(value) => json!({"status":"ok","latencyMs":session_probe.1,"persistence":value}),
+        Err(error) => {
+            json!({"status":"error","latencyMs":session_probe.1,"backend":config.session_backend,"error":error})
+        }
+    };
+
+    let local_sessions =
+        store.diagnostics_snapshot(config.diagnostics_endpoint.include_user_identifiers);
+    let security = telemetry.security_snapshot(config.diagnostics_endpoint.security_window_secs);
+    let security_alert = security
+        .get("securityAlert")
+        .and_then(Value::as_bool)
+        .unwrap_or(false);
+    let config_checks = configuration_checks(config);
+    let critical = db_diag.status != "ok"
+        || storage_status.get("status").and_then(Value::as_str) != Some("ok")
+        || session_status.get("status").and_then(Value::as_str) != Some("ok")
+        || (config.search.required
+            && search_status.get("status").and_then(Value::as_str) != Some("ok"));
+    let degraded = !critical
+        && (security_alert
+            || db_diag.schema_aligned == Some(false)
+            || search_status.get("status").and_then(Value::as_str) == Some("degraded")
+            || config_checks
+                .iter()
+                .any(|check| check.get("severity").and_then(Value::as_str) == Some("warning")));
+
+    let response = json!({
+        "status": if critical { "error" } else if degraded { "degraded" } else { "ok" },
+        "timestampUnix": now_unix(),
+        "request": {"sourceIp": source_ip.to_string()},
+        "application": {
+            "name": "RustBox",
+            "version": env!("CARGO_PKG_VERSION"),
+            "uptimeSeconds": telemetry.started.elapsed().as_secs(),
+            "startedAtUnix": telemetry.started_at_unix,
+            "process": process_snapshot(),
+            "clusterMode": config.cluster_mode,
+        },
+        "runtimeCounters": {
+            "totalRequests": telemetry.total_requests.load(Ordering::Relaxed),
+            "clientErrors": telemetry.client_errors.load(Ordering::Relaxed),
+            "serverErrors": telemetry.server_errors.load(Ordering::Relaxed),
+            "loginAttempts": telemetry.login_attempts.load(Ordering::Relaxed),
+            "idleTasks": idle_manager.task_count(),
+            "idleSubscribers": idle_manager.subscriber_count(),
+            "idleConnections": idle_manager.diagnostics_snapshot(config.diagnostics_endpoint.include_user_identifiers),
+        },
+        "configuration": sanitized_config(config),
+        "checks": config_checks,
+        "database": db_diag,
+        "storage": {
+            "backend": config.effective_storage_backend(),
+            "health": storage_status,
+        },
+        "search": search_status,
+        "sessions": {
+            "backend": config.session_backend,
+            "health": session_status,
+            "localNode": local_sessions,
+        },
+        "security": security,
+    });
+
+    harden_diagnostics_response(
+        (
+            if critical {
+                StatusCode::SERVICE_UNAVAILABLE
+            } else {
+                StatusCode::OK
+            },
+            Json(response),
+        )
+            .into_response(),
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn diagnostics_secret_compare_matches_only_exact_value() {
+        assert!(constant_time_secret_eq(
+            "abcdefghijklmnopqrstuvwx",
+            "abcdefghijklmnopqrstuvwx"
+        ));
+        assert!(!constant_time_secret_eq(
+            "abcdefghijklmnopqrstuvwx",
+            "abcdefghijklmnopqrstuvwy"
+        ));
+    }
+
+    #[test]
+    fn diagnostics_url_redaction_removes_credentials_and_query() {
+        assert_eq!(
+            sanitize_url(Some(
+                "postgres://user:secret@db.example.test:5432/rustbox?sslmode=require"
+            )),
+            Some("postgres://db.example.test:5432/rustbox".to_string())
+        );
+        assert_eq!(
+            sanitize_url(Some("redis://:secret@redis.example.test:6379/2")),
+            Some("redis://redis.example.test:6379/2".to_string())
+        );
+    }
+
+    #[test]
+    fn diagnostics_client_ip_ignores_untrusted_forwarded_header() {
+        let config = AppConfig {
+            trusted_proxies: Some("127.0.0.1/32".to_string()),
+            ..AppConfig::default()
+        };
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", HeaderValue::from_static("203.0.113.42"));
+        let peer: IpAddr = "198.51.100.10".parse().unwrap();
+        assert_eq!(effective_client_ip(&config, &headers, peer), peer);
+    }
+
+    #[test]
+    fn diagnostics_client_ip_uses_forwarded_header_only_from_trusted_proxy() {
+        let config = AppConfig {
+            trusted_proxies: Some("127.0.0.1/32".to_string()),
+            ..AppConfig::default()
+        };
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", HeaderValue::from_static("203.0.113.42"));
+        assert_eq!(
+            effective_client_ip(&config, &headers, "127.0.0.1".parse().unwrap()),
+            "203.0.113.42".parse::<IpAddr>().unwrap()
+        );
+    }
+
+    #[test]
+    fn diagnostics_endpoint_rejects_proxy_headers_from_untrusted_peer() {
+        let config = AppConfig::default();
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", HeaderValue::from_static("203.0.113.42"));
+        assert!(diagnostics_client_ip(&config, &headers, "127.0.0.1".parse().unwrap(),).is_err());
+    }
+
+    #[test]
+    fn diagnostics_endpoint_rejects_malformed_xff_from_trusted_proxy() {
+        let config = AppConfig {
+            trusted_proxies: Some("127.0.0.1/32".to_string()),
+            ..AppConfig::default()
+        };
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", HeaderValue::from_static("not-an-ip"));
+        assert!(diagnostics_client_ip(&config, &headers, "127.0.0.1".parse().unwrap(),).is_err());
+    }
+
+    #[test]
+    fn diagnostics_endpoint_accepts_xff_from_configured_trusted_proxy() {
+        let config = AppConfig {
+            trusted_proxies: Some("127.0.0.1/32".to_string()),
+            ..AppConfig::default()
+        };
+        let mut headers = HeaderMap::new();
+        headers.insert("x-forwarded-for", HeaderValue::from_static("203.0.113.42"));
+        assert_eq!(
+            diagnostics_client_ip(&config, &headers, "127.0.0.1".parse().unwrap()).unwrap(),
+            "203.0.113.42".parse::<IpAddr>().unwrap()
+        );
+    }
+}

src/routes/tests.rs

@@ -12,7 +12,8 @@ use tower_governor::key_extractor::KeyExtractor;
 
 use crate::imap::client::mock::MockImapClient;
 use crate::imap::client::{
-    EmailAddress, ImapAttachment, ImapError, ImapFolder, ImapMessageBody, ImapMessageHeader,
+    EmailAddress, FolderStatusExtended, ImapAttachment, ImapError, ImapFolder, ImapMessageBody,
+    ImapMessageHeader,
 };
 use crate::smtp::client::SmtpError;
 use crate::smtp::client::mock::MockSmtpClient;
@@ -304,15 +305,18 @@ async fn disabled_optional_features_are_not_registered() {
 }
 
 #[tokio::test]
-async fn auth_policy_exposes_optional_feature_switches() {
+async fn auth_policy_exposes_only_login_requirements_before_authentication() {
     let dir = setup_static_dir();
     let mut config = (*test_config(dir.path().to_str().unwrap())).clone();
+    config.remember_me_enabled = true;
     config.sieve_enabled = false;
     config.diagnostics_enabled = false;
     config.about_enabled = false;
+    let store = test_store();
+    let (browser_id, account_id, token) = setup_test_account(&store, "alice@example.com");
     let app = create_router(
         Arc::new(config),
-        test_store(),
+        store,
         test_imap_client(),
         test_smtp_client(),
         test_search_engine("/tmp/oxi-test"),
@@ -321,6 +325,7 @@ async fn auth_policy_exposes_optional_feature_switches() {
     );
 
     let response = app
+        .clone()
         .oneshot(
             Request::builder()
                 .uri("/api/auth/policy")
@@ -332,13 +337,52 @@ async fn auth_policy_exposes_optional_feature_switches() {
     assert_eq!(response.status(), StatusCode::OK);
     let body = response.into_body().collect().await.unwrap().to_bytes();
     let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+    assert_eq!(json["rememberMeEnabled"], true);
+    for key in [
+        "rememberMeDays",
+        "sessionTimeoutHours",
+        "pgpEnabled",
+        "sieveEnabled",
+        "diagnosticsEnabled",
+        "aboutEnabled",
+    ] {
+        assert!(json.get(key).is_none(), "public policy leaked {key}");
+    }
+
+    let unauth = app
+        .clone()
+        .oneshot(
+            Request::builder()
+                .uri("/api/auth/session-policy")
+                .body(Body::empty())
+                .unwrap(),
+        )
+        .await
+        .unwrap();
+    assert_eq!(unauth.status(), StatusCode::UNAUTHORIZED);
+
+    let mut request = Request::builder()
+        .uri("/api/auth/session-policy")
+        .header("x-requested-with", "XMLHttpRequest");
+    for (name, value) in auth_headers(&browser_id, &account_id, &token) {
+        request = request.header(name, value);
+    }
+    let response = app
+        .oneshot(request.body(Body::empty()).unwrap())
+        .await
+        .unwrap();
+    assert_eq!(response.status(), StatusCode::OK);
+    let body = response.into_body().collect().await.unwrap().to_bytes();
+    let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
     assert_eq!(json["sieveEnabled"], false);
     assert_eq!(json["diagnosticsEnabled"], false);
     assert_eq!(json["aboutEnabled"], false);
+    assert!(json.get("rememberMeDays").is_none());
+    assert!(json.get("sessionTimeoutHours").is_none());
 }
 
 #[tokio::test]
-async fn security_headers_are_opt_in() {
+async fn security_headers_are_opt_in_and_content_type_aware() {
     let dir = setup_static_dir();
     let app = create_router(
         test_config(dir.path().to_str().unwrap()),
@@ -350,43 +394,134 @@ async fn security_headers_are_opt_in() {
         test_idle_manager(),
     );
     let response = app
-        .oneshot(
+        .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
-            Request::builder()
-                .uri("/api/health")
-                .body(Body::empty())
-                .unwrap(),
-        )
         .await
         .unwrap();
     assert!(response.headers().get("content-security-policy").is_none());
-
+    assert!(response.headers().get("x-content-type-options").is_none());
-    let mut config = (*test_config(dir.path().to_str().unwrap())).clone();
+    let disabled_api = create_router(
-    config.security_headers_enabled = true;
+        test_config(dir.path().to_str().unwrap()),
-    let app = create_router(
-        Arc::new(config),
         test_store(),
         test_imap_client(),
         test_smtp_client(),
         test_search_engine("/tmp/oxi-test"),
         test_event_bus(),
         test_idle_manager(),
-    );
+    )
-    let response = app
+    .oneshot(
-        .oneshot(
+        Request::builder()
-            Request::builder()
+            .uri("/api/health")
-                .uri("/api/health")
+            .body(Body::empty())
-                .body(Body::empty())
+            .unwrap(),
-                .unwrap(),
+    )
-        )
+    .await
-        .await
+    .unwrap();
-        .unwrap();
-    assert_eq!(response.headers()["x-frame-options"], "DENY");
     assert!(
-        response.headers()["content-security-policy"]
+        disabled_api
-            .to_str()
+            .headers()
-            .unwrap()
+            .get("x-content-type-options")
-            .contains("default-src 'self'")
+            .is_none()
     );
+    assert!(
+        disabled_api
+            .headers()
+            .get("cross-origin-resource-policy")
+            .is_none()
+    );
+    assert!(
+        disabled_api
+            .headers()
+            .get("content-security-policy")
+            .is_none()
+    );
+    assert!(disabled_api.headers().get("x-frame-options").is_none());
+
+    let mut config = (*test_config(dir.path().to_str().unwrap())).clone();
+    config.security_headers_enabled = true;
+    let config = Arc::new(config);
+
+    let html = create_router(
+        config.clone(),
+        test_store(),
+        test_imap_client(),
+        test_smtp_client(),
+        test_search_engine("/tmp/oxi-test"),
+        test_event_bus(),
+        test_idle_manager(),
+    )
+    .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
+    .await
+    .unwrap();
+    assert_eq!(html.headers()["x-content-type-options"], "nosniff");
+    assert_eq!(html.headers()["x-frame-options"], "DENY");
+    assert_eq!(html.headers()["referrer-policy"], "no-referrer");
+    assert_eq!(
+        html.headers()["permissions-policy"],
+        "camera=(), microphone=(), geolocation=()"
+    );
+    assert_eq!(html.headers()["cross-origin-opener-policy"], "same-origin");
+    let html_csp = html.headers()["content-security-policy"].to_str().unwrap();
+    assert!(html_csp.contains("default-src 'self'"));
+    assert!(html_csp.contains("script-src 'self';"));
+    assert!(html_csp.contains("script-src-attr 'none'"));
+    assert!(html_csp.contains("style-src 'self'; style-src-attr 'unsafe-inline'"));
+    assert!(!html_csp.contains("style-src 'self' 'unsafe-inline'"));
+    assert!(!html_csp.contains("unsafe-inline'; script-src"));
+    assert!(!html_csp.contains("script-src 'self' 'unsafe-inline'"));
+
+    let css = create_router(
+        config.clone(),
+        test_store(),
+        test_imap_client(),
+        test_smtp_client(),
+        test_search_engine("/tmp/oxi-test"),
+        test_event_bus(),
+        test_idle_manager(),
+    )
+    .oneshot(
+        Request::builder()
+            .uri("/assets/app.css")
+            .body(Body::empty())
+            .unwrap(),
+    )
+    .await
+    .unwrap();
+    assert_eq!(css.headers()["x-content-type-options"], "nosniff");
+    assert_eq!(css.headers()["referrer-policy"], "no-referrer");
+    assert_eq!(css.headers()["cross-origin-resource-policy"], "same-origin");
+    assert!(css.headers().get("x-frame-options").is_none());
+    assert!(css.headers().get("permissions-policy").is_none());
+    assert!(css.headers().get("cross-origin-opener-policy").is_none());
+    assert!(css.headers().get("content-security-policy").is_none());
+
+    let api = create_router(
+        config,
+        test_store(),
+        test_imap_client(),
+        test_smtp_client(),
+        test_search_engine("/tmp/oxi-test"),
+        test_event_bus(),
+        test_idle_manager(),
+    )
+    .oneshot(
+        Request::builder()
+            .uri("/api/health")
+            .body(Body::empty())
+            .unwrap(),
+    )
+    .await
+    .unwrap();
+    assert_eq!(api.headers()["x-content-type-options"], "nosniff");
+    assert_eq!(api.headers()["cache-control"], "no-store");
+    assert_eq!(api.headers()["cross-origin-resource-policy"], "same-origin");
+    assert_eq!(
+        api.headers()["content-security-policy"],
+        "frame-ancestors 'none'"
+    );
+    assert_eq!(api.headers()["x-frame-options"], "DENY");
+    assert!(api.headers().get("referrer-policy").is_none());
+    assert!(api.headers().get("permissions-policy").is_none());
+    assert!(api.headers().get("cross-origin-opener-policy").is_none());
 }
 
 #[tokio::test]
@@ -945,6 +1080,77 @@ async fn get_folders_returns_200_with_folder_list() {
     assert_eq!(folders[1]["name"], "Sent");
 }
 
+#[tokio::test]
+async fn folder_refresh_uses_server_counts_without_relisting_fresh_folder_tree() {
+    let static_dir = setup_static_dir();
+    let data_dir = TempDir::new().unwrap();
+    let config = test_config_with_imap(
+        static_dir.path().to_str().unwrap(),
+        data_dir.path().to_str().unwrap(),
+    );
+    let store = test_store();
+    let (browser_id, account_id, token) = setup_test_account(&store, "alice@example.com");
+    let user_hash = crate::auth::user_data::hash_email("alice@example.com");
+    provision_user_db(data_dir.path().to_str().unwrap(), &user_hash);
+
+    let conn = crate::db::pool::open_user_db(data_dir.path().to_str().unwrap(), &user_hash)
+        .expect("open user DB");
+    crate::db::folders::upsert_folder(
+        &conn,
+        "INBOX",
+        Some("/"),
+        None,
+        "\\HasNoChildren",
+        true,
+        3444,
+        1,
+        1,
+        10,
+    )
+    .unwrap();
+    crate::db::folders::touch_all_folders(&conn).unwrap();
+    drop(conn);
+
+    let mock = MockImapClient::new().with_folder_status_extended(FolderStatusExtended {
+        uid_validity: 1,
+        exists: 3444,
+        uid_next: 3445,
+        unseen: 12,
+        highest_modseq: 11,
+    });
+    let app = create_router(
+        config,
+        store,
+        Arc::new(mock),
+        test_smtp_client(),
+        test_search_engine(data_dir.path().to_str().unwrap()),
+        test_event_bus(),
+        test_idle_manager(),
+    );
+
+    let mut request = Request::builder()
+        .uri("/api/folders?refresh=true")
+        .header("x-requested-with", "XMLHttpRequest");
+    for (name, value) in auth_headers(&browser_id, &account_id, &token) {
+        request = request.header(name, value);
+    }
+    let response = app
+        .oneshot(request.body(Body::empty()).unwrap())
+        .await
+        .unwrap();
+    assert_eq!(response.status(), StatusCode::OK);
+    let body = response.into_body().collect().await.unwrap().to_bytes();
+    let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+    let inbox = json["folders"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .find(|folder| folder["name"] == "INBOX")
+        .expect("INBOX remains in the cached folder tree");
+    assert_eq!(inbox["total_count"], 3444);
+    assert_eq!(inbox["unread_count"], 12);
+}
+
 #[tokio::test]
 async fn get_folders_returns_503_when_imap_fails() {
     let static_dir = setup_static_dir();

src/search/engine.rs

@@ -219,6 +219,25 @@ impl SearchEngine {
         }
     }
 
+    pub async fn diagnostics(&self) -> Result<JsonValue, String> {
+        match &self.backend {
+            SearchBackend::Disabled => Ok(json!({
+                "backend": "disabled",
+                "status": "disabled"
+            })),
+            SearchBackend::LocalTantivy { base_dir } => {
+                std::fs::create_dir_all(base_dir)
+                    .map_err(|e| format!("failed to prepare local search directory: {e}"))?;
+                Ok(json!({
+                    "backend": "local_tantivy",
+                    "status": "ok",
+                    "path": base_dir,
+                }))
+            }
+            SearchBackend::OpenSearch { backend, .. } => backend.diagnostics().await,
+        }
+    }
+
     pub fn open_user_index(&self, user_hash: &str) -> Result<UserIndex, String> {
         match &self.backend {
             SearchBackend::Disabled => Err("search index is disabled by configuration".to_string()),
@@ -695,9 +714,6 @@ impl LocalUserIndex {
 
 impl OpenSearchBackend {
     fn event_lease_secs(&self) -> u64 {
-        // A mutation can probe/create the index and then write the document.
-        // Account for failover across all configured URLs and keep a safety margin so
-        // another worker cannot reclaim the same document while this request is alive.
         self.request_timeout_secs
             .saturating_mul(self.urls.len().max(1) as u64)
             .saturating_mul(4)
@@ -796,6 +812,61 @@ impl OpenSearchBackend {
         }
     }
 
+    async fn diagnostics(&self) -> Result<JsonValue, String> {
+        let (status, body) = self
+            .request(Method::GET, "_cluster/health?local=true", None)
+            .await?;
+        if !status.is_success() {
+            return Err(format!("OpenSearch health check failed ({status}): {body}"));
+        }
+        self.ensure_index().await?;
+        let health: JsonValue = serde_json::from_str(&body)
+            .map_err(|e| format!("invalid OpenSearch health response: {e}"))?;
+        let (count_status, count_body) = self
+            .request(Method::GET, &format!("{}/_count", self.index_name), None)
+            .await?;
+        if !count_status.is_success() {
+            return Err(format!(
+                "OpenSearch index count failed ({count_status}): {count_body}"
+            ));
+        }
+        let document_count = serde_json::from_str::<JsonValue>(&count_body)
+            .map_err(|e| format!("invalid OpenSearch count response: {e}"))?
+            .get("count")
+            .and_then(JsonValue::as_u64)
+            .ok_or_else(|| {
+                "OpenSearch count response does not contain a numeric count".to_string()
+            })?;
+        let cluster_status = health
+            .get("status")
+            .and_then(JsonValue::as_str)
+            .unwrap_or("unknown");
+        if cluster_status.eq_ignore_ascii_case("red") {
+            return Err("OpenSearch cluster health is red".to_string());
+        }
+        let diagnostics_status = if cluster_status.eq_ignore_ascii_case("green") {
+            "ok"
+        } else {
+            "degraded"
+        };
+        Ok(json!({
+            "backend": "opensearch",
+            "status": diagnostics_status,
+            "clusterStatus": cluster_status,
+            "clusterName": health.get("cluster_name").and_then(JsonValue::as_str),
+            "numberOfNodes": health.get("number_of_nodes").and_then(JsonValue::as_u64),
+            "numberOfDataNodes": health.get("number_of_data_nodes").and_then(JsonValue::as_u64),
+            "activePrimaryShards": health.get("active_primary_shards").and_then(JsonValue::as_u64),
+            "activeShards": health.get("active_shards").and_then(JsonValue::as_u64),
+            "relocatingShards": health.get("relocating_shards").and_then(JsonValue::as_u64),
+            "initializingShards": health.get("initializing_shards").and_then(JsonValue::as_u64),
+            "unassignedShards": health.get("unassigned_shards").and_then(JsonValue::as_u64),
+            "index": self.index_name,
+            "documentCount": document_count,
+            "configuredUrls": self.urls.len(),
+        }))
+    }
+
     fn document_id(user_hash: &str, uid: u32, folder: &str) -> String {
         format!(
             "{:x}",

src/session_store/database.rs

@@ -4,7 +4,7 @@ use async_trait::async_trait;
 use rusqlite::{Connection, params};
 use sqlx::{FromRow, MySqlPool, PgPool};
 
-use super::{PersistedSession, SessionPersistence};
+use super::{PersistedSession, SessionPersistence, SessionPersistenceDiagnostics};
 use crate::config::AppConfig;
 use crate::queries;
 
@@ -148,11 +148,6 @@ pub struct DatabaseSessionStore {
 
 impl DatabaseSessionStore {
     pub async fn connect(config: &AppConfig) -> Result<Self, String> {
-        // Schema ownership is centralized in db::pool::configure().  Calling it here
-        // keeps direct/test construction safe, while the normal application startup
-        // hits the OnceLock fast path.  Do not run schema.sql again from this store:
-        // that used to duplicate DDL for SQLite/MySQL/PostgreSQL and produced repeated
-        // PostgreSQL "relation already exists, skipping" NOTICE messages.
         crate::db::pool::configure(config).await?;
 
         let pool = match config.database_backend.as_str() {
@@ -425,6 +420,61 @@ impl SessionPersistence for DatabaseSessionStore {
         }
     }
 
+    async fn diagnostics(&self, now_unix: u64) -> Result<SessionPersistenceDiagnostics, String> {
+        let (backend, active_sessions, unique_users, unique_browsers, latest_accessed_unix) =
+            match &self.pool {
+                Pool::Sqlite(path) => {
+                    let path = path.clone();
+                    let row = sqlite_task(path, move |conn| {
+                    conn.query_row(
+                        "SELECT COUNT(*), COUNT(DISTINCT user_hash), COUNT(DISTINCT browser_id), MAX(last_accessed_unix) FROM sessions WHERE (last_accessed_unix + timeout_secs) >= ?1",
+                        params![now_unix as i64],
+                        |row| Ok((row.get::<_, i64>(0)?, row.get::<_, i64>(1)?, row.get::<_, i64>(2)?, row.get::<_, Option<i64>>(3)?)),
+                    )
+                    .map_err(|e| format!("failed to query SQLite session diagnostics: {e}"))
+                })
+                .await?;
+                    ("database/sqlite", row.0, row.1, row.2, row.3)
+                }
+                Pool::Mysql(pool) => {
+                    let row: (i64, i64, i64, Option<i64>) = sqlx::query_as(
+                    "SELECT COUNT(*), COUNT(DISTINCT user_hash), COUNT(DISTINCT browser_id), MAX(last_accessed_unix) FROM sessions WHERE (last_accessed_unix + timeout_secs) >= ?"
+                )
+                .bind(now_unix as i64)
+                .fetch_one(pool)
+                .await
+                .map_err(|e| format!("failed to query MySQL session diagnostics: {e}"))?;
+                    ("database/mysql", row.0, row.1, row.2, row.3)
+                }
+                Pool::Pgsql(pool) => {
+                    let row: (i64, i64, i64, Option<i64>) = sqlx::query_as(
+                    "SELECT COUNT(*), COUNT(DISTINCT user_hash), COUNT(DISTINCT browser_id), MAX(last_accessed_unix) FROM sessions WHERE (last_accessed_unix + timeout_secs) >= $1"
+                )
+                .bind(now_unix as i64)
+                .fetch_one(pool)
+                .await
+                .map_err(|e| format!("failed to query PostgreSQL session diagnostics: {e}"))?;
+                    ("database/pgsql", row.0, row.1, row.2, row.3)
+                }
+            };
+        Ok(SessionPersistenceDiagnostics {
+            backend: backend.to_string(),
+            status: "ok".to_string(),
+            active_sessions: active_sessions.max(0) as usize,
+            unique_users: unique_users.max(0) as usize,
+            unique_browsers: unique_browsers.max(0) as usize,
+            latest_accessed_unix: latest_accessed_unix.and_then(|value| u64::try_from(value).ok()),
+            truncated: false,
+            engine_version: None,
+            connected_clients: None,
+            blocked_clients: None,
+            used_memory_bytes: None,
+            server_uptime_secs: None,
+            role: None,
+            master_link_status: None,
+        })
+    }
+
     async fn purge_expired(&self, now_unix: u64) -> Result<u64, String> {
         match &self.pool {
             Pool::Sqlite(path) => {

src/session_store/mod.rs

@@ -7,6 +7,24 @@ use serde::{Deserialize, Serialize};
 
 use crate::config::AppConfig;
 
+#[derive(Debug, Clone, Serialize)]
+pub struct SessionPersistenceDiagnostics {
+    pub backend: String,
+    pub status: String,
+    pub active_sessions: usize,
+    pub unique_users: usize,
+    pub unique_browsers: usize,
+    pub latest_accessed_unix: Option<u64>,
+    pub truncated: bool,
+    pub engine_version: Option<String>,
+    pub connected_clients: Option<u64>,
+    pub blocked_clients: Option<u64>,
+    pub used_memory_bytes: Option<u64>,
+    pub server_uptime_secs: Option<u64>,
+    pub role: Option<String>,
+    pub master_link_status: Option<String>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct PersistedSession {
     pub token: String,
@@ -45,6 +63,7 @@ pub trait SessionPersistence: Send + Sync {
     async fn delete_account(&self, account_id: &str) -> Result<bool, String>;
     async fn delete_browser(&self, browser_id: &str) -> Result<(), String>;
     async fn purge_expired(&self, now_unix: u64) -> Result<u64, String>;
+    async fn diagnostics(&self, now_unix: u64) -> Result<SessionPersistenceDiagnostics, String>;
 }
 
 pub async fn from_config(

src/session_store/redis_store.rs

@@ -1,7 +1,7 @@
 use async_trait::async_trait;
 use redis::AsyncCommands;
 
-use super::{PersistedSession, SessionPersistence};
+use super::{PersistedSession, SessionPersistence, SessionPersistenceDiagnostics};
 use crate::config::AppConfig;
 
 #[derive(Clone)]
@@ -23,6 +23,14 @@ pub struct RedisSessionStore {
     mode: RedisMode,
 }
 
+fn redis_info_value<'a>(info: &'a str, key: &str) -> Option<&'a str> {
+    info.lines().find_map(|line| {
+        let line = line.trim_end_matches('\r');
+        let (name, value) = line.split_once(':')?;
+        (name == key).then_some(value.trim())
+    })
+}
+
 impl RedisSessionStore {
     pub async fn connect(config: &AppConfig) -> Result<Self, String> {
         let mode = if let Some(url) = config
@@ -274,6 +282,107 @@ impl SessionPersistence for RedisSessionStore {
         Ok(())
     }
 
+    async fn diagnostics(&self, now_unix: u64) -> Result<SessionPersistenceDiagnostics, String> {
+        use std::collections::HashSet;
+
+        const MAX_SCAN_SESSIONS: usize = 5000;
+        let mut con = self.connection().await?;
+        let pong: String = redis::cmd("PING")
+            .query_async(&mut con)
+            .await
+            .map_err(|e| format!("Redis PING failed: {e}"))?;
+        if !pong.eq_ignore_ascii_case("PONG") {
+            return Err(format!("unexpected Redis PING response: {pong}"));
+        }
+        let info: String = redis::cmd("INFO")
+            .query_async(&mut con)
+            .await
+            .map_err(|e| format!("Redis INFO failed: {e}"))?;
+
+        let mut cursor = 0u64;
+        let mut seen = 0usize;
+        let mut active = 0usize;
+        let mut users = HashSet::new();
+        let mut browsers = HashSet::new();
+        let mut latest = None;
+        let mut truncated = false;
+
+        loop {
+            let (next_cursor, keys): (u64, Vec<String>) = redis::cmd("SCAN")
+                .arg(cursor)
+                .arg("MATCH")
+                .arg("rustbox:session:*")
+                .arg("COUNT")
+                .arg(250)
+                .query_async(&mut con)
+                .await
+                .map_err(|e| format!("Redis SCAN failed: {e}"))?;
+
+            if !keys.is_empty() {
+                let remaining = MAX_SCAN_SESSIONS.saturating_sub(seen);
+                if remaining == 0 {
+                    truncated = true;
+                    break;
+                }
+                let keys = if keys.len() > remaining {
+                    truncated = true;
+                    &keys[..remaining]
+                } else {
+                    &keys[..]
+                };
+                let mut command = redis::cmd("MGET");
+                for key in keys {
+                    command.arg(key);
+                }
+                let values: Vec<Option<String>> = command
+                    .query_async(&mut con)
+                    .await
+                    .map_err(|e| format!("Redis MGET diagnostics failed: {e}"))?;
+                seen += keys.len();
+                for raw in values.into_iter().flatten() {
+                    let Ok(session) = serde_json::from_str::<PersistedSession>(&raw) else {
+                        continue;
+                    };
+                    if session.expired_at(now_unix) {
+                        continue;
+                    }
+                    active += 1;
+                    users.insert(session.user_hash);
+                    browsers.insert(session.browser_id);
+                    latest = Some(latest.map_or(session.last_accessed_unix, |value: u64| {
+                        value.max(session.last_accessed_unix)
+                    }));
+                }
+            }
+
+            if truncated || next_cursor == 0 {
+                break;
+            }
+            cursor = next_cursor;
+        }
+
+        Ok(SessionPersistenceDiagnostics {
+            backend: "redis".to_string(),
+            status: "ok".to_string(),
+            active_sessions: active,
+            unique_users: users.len(),
+            unique_browsers: browsers.len(),
+            latest_accessed_unix: latest,
+            truncated,
+            engine_version: redis_info_value(&info, "redis_version").map(str::to_string),
+            connected_clients: redis_info_value(&info, "connected_clients")
+                .and_then(|value| value.parse().ok()),
+            blocked_clients: redis_info_value(&info, "blocked_clients")
+                .and_then(|value| value.parse().ok()),
+            used_memory_bytes: redis_info_value(&info, "used_memory")
+                .and_then(|value| value.parse().ok()),
+            server_uptime_secs: redis_info_value(&info, "uptime_in_seconds")
+                .and_then(|value| value.parse().ok()),
+            role: redis_info_value(&info, "role").map(str::to_string),
+            master_link_status: redis_info_value(&info, "master_link_status").map(str::to_string),
+        })
+    }
+
     async fn purge_expired(&self, _now_unix: u64) -> Result<u64, String> {
         Ok(0)
     }

src/ui.rs

@@ -9,6 +9,7 @@ use crate::config::AppConfig;
 const INDEX_HTML: &str = include_str!("web/index.html");
 const APP_CSS: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/rustbox-ui.css"));
 const APP_JS: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/rustbox-ui.js"));
+const THEME_BOOTSTRAP_JS: &[u8] = include_bytes!("web/theme-bootstrap.js");
 const ICONS: &[u8] = include_bytes!("web/icons.svg");
 const I18N_EN: &[u8] = include_bytes!("web/i18n/en.json");
 const I18N_PL: &[u8] = include_bytes!("web/i18n/pl.json");
@@ -27,7 +28,6 @@ fn bytes_response(
         [
             (header::CONTENT_TYPE, content_type),
             (header::CACHE_CONTROL, cache),
-            (header::X_CONTENT_TYPE_OPTIONS, "nosniff"),
         ],
         body,
     )
@@ -48,6 +48,7 @@ pub async fn serve_ui(uri: Uri, Extension(config): Extension<Arc<AppConfig>>) ->
 
     let versioned_css = format!("assets/app.{ASSET_ID}.css");
     let versioned_js = format!("assets/app.{ASSET_ID}.js");
+    let versioned_theme_bootstrap = format!("assets/theme-bootstrap.{ASSET_ID}.js");
     if relative == versioned_css.as_str() {
         return bytes_response(
             "text/css; charset=utf-8",
@@ -62,10 +63,22 @@ pub async fn serve_ui(uri: Uri, Extension(config): Extension<Arc<AppConfig>>) ->
             APP_JS,
         );
     }
+    if relative == versioned_theme_bootstrap.as_str() {
+        return bytes_response(
+            "text/javascript; charset=utf-8",
+            "public, max-age=31536000, immutable",
+            THEME_BOOTSTRAP_JS,
+        );
+    }
 
     match relative {
         "assets/app.css" => bytes_response("text/css; charset=utf-8", "no-store", APP_CSS),
         "assets/app.js" => bytes_response("text/javascript; charset=utf-8", "no-store", APP_JS),
+        "assets/theme-bootstrap.js" => bytes_response(
+            "text/javascript; charset=utf-8",
+            "no-store",
+            THEME_BOOTSTRAP_JS,
+        ),
         "assets/icons.svg" => bytes_response("image/svg+xml", "no-store", ICONS),
         "assets/i18n/en.json" => {
             bytes_response("application/json; charset=utf-8", "no-store", I18N_EN)
@@ -78,7 +91,6 @@ pub async fn serve_ui(uri: Uri, Extension(config): Extension<Arc<AppConfig>>) ->
             [
                 (header::CONTENT_TYPE, "image/svg+xml"),
                 (header::CACHE_CONTROL, "no-store"),
-                (header::X_CONTENT_TYPE_OPTIONS, "nosniff"),
             ],
             FAVICON,
         )
@@ -121,7 +133,6 @@ pub async fn serve_ui(uri: Uri, Extension(config): Extension<Arc<AppConfig>>) ->
                 [
                     (header::CONTENT_TYPE, "text/html; charset=utf-8"),
                     (header::CACHE_CONTROL, "no-store"),
-                    (header::X_CONTENT_TYPE_OPTIONS, "nosniff"),
                 ],
                 html,
             )

src/web/css/20-shell.css

@@ -158,15 +158,22 @@
 .indexing-indicator svg {
   width: 16px;
   height: 16px;
+}
+
+.indexing-indicator.active svg {
   animation: rustbox-indexing-spin .9s linear infinite;
 }
 
 @keyframes rustbox-indexing-spin {
-  to { transform: rotate(360deg); }
+  to {
+    transform: rotate(360deg);
+  }
 }
 
 @media (prefers-reduced-motion: reduce) {
-  .indexing-indicator svg { animation: none; }
+  .indexing-indicator svg {
+    animation: none;
+  }
 }
 
 .account-summary {
@@ -216,6 +223,8 @@
 }
 
 .folder-pane {
+  container-name: folder-pane;
+  container-type: inline-size;
   display: flex;
   flex-direction: column;
   padding: 10px;

src/web/css/30-mail.css

@@ -49,10 +49,47 @@
 }
 
 .folder-count.unread {
+  color: var(--subtle);
+}
+
+.folder-count .folder-unread,
+.folder-count.unread .folder-count-compact {
   color: var(--accent);
   font-weight: 700;
 }
 
+.folder-count-wide {
+  display: inline-flex;
+  align-items: baseline;
+  gap: 0;
+  white-space: nowrap;
+}
+
+.folder-count-compact {
+  display: none;
+}
+
+.folder-count .folder-total,
+.folder-count .folder-unread,
+.folder-count-compact {
+  font-variant-numeric: tabular-nums;
+}
+
+.folder-count .folder-separator {
+  color: var(--subtle);
+  font-weight: 400;
+}
+
+@container folder-pane (max-width: 205px) {
+  .folder-count-wide {
+    display: none;
+  }
+
+  .folder-count-compact {
+    display: inline;
+  }
+}
+
 .message-pane {
   display: grid;
   grid-template-rows: auto minmax(0, 1fr) auto;

src/web/index.html

@@ -12,16 +12,7 @@
   <meta name="color-scheme" content="dark light">
   <meta name="description" content="RustBox webmail">
   <title>RustBox</title>
-  <script>
+  <script src="__RUSTBOX_ASSET_PREFIX__/assets/theme-bootstrap.__RUSTBOX_ASSET_ID__.js"></script>
-    (() => {
-      const root = document.documentElement;
-      const configured = root.dataset.defaultTheme || "system";
-      root.dataset.theme = configured === "system"
-        ? (matchMedia("(prefers-color-scheme: light)").matches ? "light" : "dark")
-        : configured;
-      root.dataset.interfaceSkin = root.dataset.defaultInterfaceSkin || "rustbox";
-    })();
-  </script>
   <link rel="icon" href="__RUSTBOX_ASSET_PREFIX__/favicon.svg" type="image/svg+xml">
   <link rel="stylesheet" href="__RUSTBOX_ASSET_PREFIX__/assets/app.__RUSTBOX_ASSET_ID__.css">
 </head>
@@ -77,13 +68,13 @@
         <kbd>/</kbd>
       </form>
       <div class="appbar-actions">
+        <span id="indexing-indicator" class="indexing-indicator hidden" role="status" aria-live="polite"
+          title="Mail synchronization" aria-label="Mail synchronization"><svg aria-hidden="true">
+            <use href="__RUSTBOX_ASSET_PREFIX__/assets/icons.svg#icon-refresh-cw"></use>
+          </svg></span>
         <button id="contacts-btn" class="icon-button" type="button" title="Contacts" aria-label="Contacts"><svg>
             <use href="__RUSTBOX_ASSET_PREFIX__/assets/icons.svg#icon-user-round"></use>
           </svg></button>
-        <span id="indexing-indicator" class="indexing-indicator hidden" role="status" aria-live="polite"
-          title="Indexing messages" aria-label="Indexing messages"><svg aria-hidden="true">
-            <use href="__RUSTBOX_ASSET_PREFIX__/assets/icons.svg#icon-refresh-cw"></use>
-          </svg></span>
         <button id="calendar-btn" class="icon-button" type="button" title="Calendar" aria-label="Calendar"><svg>
             <use href="__RUSTBOX_ASSET_PREFIX__/assets/icons.svg#icon-calendar-days"></use>
           </svg></button>

src/web/js/00-bootstrap.js

@@ -33,7 +33,7 @@
     pgpKeys: [],
     pgpPrefs: { wkdEnabled: true, hkpEnabled: false, requireTrustedEncryption: false },
     pgpRecipientStatus: [],
-    authPolicy: { rememberMeEnabled: true, rememberMeDays: 30, sessionTimeoutHours: 24, pgpEnabled: true, sieveEnabled: true, diagnosticsEnabled: true, aboutEnabled: true },
+    authPolicy: { rememberMeEnabled: true, pgpEnabled: false, sieveEnabled: false, diagnosticsEnabled: false, aboutEnabled: false },
     contacts: [],
     trustedSenders: new Set(),
     contactGroups: [],
@@ -63,6 +63,11 @@
     realtimeNotifiedMessages: new Map(),
     realtimeWatchedFolder: null,
     indexingActive: false,
+    indexingPending: 0,
+    imapSyncActive: false,
+    imapSyncFolder: null,
+    imapSyncPending: 0,
+    imapSyncInventoryPending: 0,
     calendarReminderTimer: null,
     composeDraftId: null,
     composeAttachments: [],

src/web/js/20-preferences-auth.js

@@ -481,17 +481,40 @@ function applyFeatureAvailability() {
 
 async function loadAuthPolicy() {
   try {
-    state.authPolicy = await request("/auth/policy", { method: "GET" });
+    const policy = await request("/auth/policy", { method: "GET" });
+    state.authPolicy = { ...state.authPolicy, ...policy };
   } catch (_) {
-    state.authPolicy = { rememberMeEnabled: true, rememberMeDays: 30, sessionTimeoutHours: 24, pgpEnabled: true, sieveEnabled: true, diagnosticsEnabled: true, aboutEnabled: true };
+    state.authPolicy = { ...state.authPolicy, rememberMeEnabled: true };
+  }
+  const enabled = state.authPolicy.rememberMeEnabled !== false;
+  ["#login-remember-row", "#add-account-remember-row"].forEach((selector) => $(selector)?.classList.toggle("hidden", !enabled));
+  ["#login-remember", "#add-account-remember"].forEach((selector) => {
+    const input = $(selector);
+    if (!input) return;
+    input.disabled = !enabled;
+    if (!enabled) input.checked = false;
+  });
+  ["#login-remember-label", "#add-account-remember-label"].forEach((selector) => {
+    const label = $(selector);
+    if (label) label.textContent = "Keep me signed in";
+  });
+}
+
+async function loadSessionPolicy() {
+  try {
+    const policy = await request("/auth/session-policy", { method: "GET" });
+    state.authPolicy = { ...state.authPolicy, ...policy };
+  } catch (_) {
+    state.authPolicy = {
+      ...state.authPolicy,
+      pgpEnabled: false,
+      sieveEnabled: false,
+      diagnosticsEnabled: false,
+      aboutEnabled: false,
+    };
   }
   setOpenPgpAvailability(state.authPolicy.pgpEnabled !== false);
   applyFeatureAvailability();
-  const enabled = state.authPolicy.rememberMeEnabled !== false;
-  ["#login-remember-row", "#add-account-remember-row"].forEach((selector) => $(selector)?.classList.toggle("hidden", !enabled));
-  ["#login-remember", "#add-account-remember"].forEach((selector) => { const input = $(selector); if (input && !enabled) { input.checked = false; input.disabled = true; } });
-  const days = Number(state.authPolicy.rememberMeDays || 30);
-  ["#login-remember-label", "#add-account-remember-label"].forEach((selector) => { const label = $(selector); if (label) label.textContent = `Keep me signed in (${days} days)`; });
 }
 
 async function loadAccounts() {
@@ -607,9 +630,11 @@ async function reloadActiveAccount() {
   state.selectedMessages.clear();
   state.selectionMode = false;
   closeReader();
+  await loadSessionPolicy();
   await loadPreferences();
   await loadMailPreferences();
-  await loadOpenPgp();
+  if (state.authPolicy.pgpEnabled !== false) await loadOpenPgp();
+  else setOpenPgpAvailability(false);
   await loadIdentities();
   await loadFolders(true);
   await loadSpecialFolders();
@@ -684,9 +709,11 @@ async function login(event) {
     state.accountId = data.account.id;
     localStorage.setItem("rustbox.activeAccount", state.accountId);
     await loadAccounts();
+    await loadSessionPolicy();
     await loadPreferences();
     await loadMailPreferences();
-    await loadOpenPgp();
+    if (state.authPolicy.pgpEnabled !== false) await loadOpenPgp();
+    else setOpenPgpAvailability(false);
     await loadIdentities();
     await loadFolders(true);
     await loadSpecialFolders();

src/web/js/30-folders-tags.js

@@ -86,6 +86,43 @@ function toggleFolderDrawer() {
   setFolderDrawerOpen(!$("#folder-pane")?.classList.contains("open"));
 }
 
+function folderCounterParts(folder) {
+  const total = Math.max(0, Number(folder?.total_count) || 0);
+  const unread = Math.max(0, Number(folder?.unread_count) || 0);
+  const title = unread > 0 ? `${total} messages · ${unread} unread` : `${total} messages · no unread`;
+  const wide = unread > 0
+    ? `<span class="folder-count-wide"><span class="folder-total">${total}</span><span class="folder-separator"> / </span><span class="folder-unread">${unread}</span></span>`
+    : `<span class="folder-count-wide"><span class="folder-total">${total}</span></span>`;
+  const compactValue = unread > 0 ? unread : total;
+  const compact = `<span class="folder-count-compact">${compactValue}</span>`;
+  return { total, unread, title, html: `${wide}${compact}` };
+}
+
+function updateFolderCounter(folder) {
+  if (!folder) return;
+  const parts = folderCounterParts(folder);
+  const button = $$(".folder-button").find((item) => item.dataset.folder === folder.name);
+  const counter = button?.querySelector(".folder-count");
+  if (!counter) return;
+  counter.classList.toggle("unread", parts.unread > 0);
+  counter.title = parts.title;
+  counter.innerHTML = parts.html;
+}
+
+function setFolderCounts(folderName, totalCount, unreadCount) {
+  const folder = state.folders.find((item) => item.name === folderName);
+  if (!folder) return;
+  if (Number.isFinite(Number(totalCount))) folder.total_count = Math.max(0, Number(totalCount));
+  if (Number.isFinite(Number(unreadCount))) folder.unread_count = Math.max(0, Number(unreadCount));
+  updateFolderCounter(folder);
+  if (folderName === state.folder && !state.searchContext) {
+    const total = Math.max(0, Number(folder.total_count) || 0);
+    const count = $("#message-count");
+    if (count) count.textContent = `${total} ${total === 1 ? "message" : "messages"}`;
+  }
+  updateUnreadAppBadge();
+}
+
 function renderFolders() {
   const list = $("#folder-list");
   list.replaceChildren();
@@ -109,7 +146,9 @@ function renderFolders() {
 
     const button = el("button", `folder-button ${folder.name === state.folder ? "active" : ""}`);
     button.type = "button";
-    button.innerHTML = `${svgIcon(folderIconName(folder))}<span class="folder-name" title="${escapeHtml(folder.name)}">${escapeHtml(folderLeafName(folder))}</span><span class="folder-count ${folder.unread_count ? "unread" : ""}">${folder.unread_count || folder.total_count || ""}</span>`;
+    button.dataset.folder = folder.name;
+    const counter = folderCounterParts(folder);
+    button.innerHTML = `${svgIcon(folderIconName(folder))}<span class="folder-name" title="${escapeHtml(folder.name)}">${escapeHtml(folderLeafName(folder))}</span><span class="folder-count ${counter.unread > 0 ? "unread" : ""}" title="${escapeHtml(counter.title)}">${counter.html}</span>`;
     button.addEventListener("contextmenu", (event) => { event.preventDefault(); openFolderContextMenu(event.clientX, event.clientY, folder); });
     button.addEventListener("dragover", (event) => {
       if (!event.dataTransfer?.types?.includes("application/x-rustbox-message")) return;
@@ -160,6 +199,8 @@ async function loadFolders(restoreView = false) {
   try {
     const data = await request("/folders", { method: "GET" });
     state.folders = data.folders || [];
+    setImapSyncInventoryPending(data.pending_sync_count);
+    setIndexingIndicator(state.indexingActive, data.pending_index_count);
     updateUnreadAppBadge();
     loadCollapsedFolders();
     const inbox = state.folders.find((folder) => folder.name.toUpperCase() === "INBOX");
@@ -172,6 +213,7 @@ async function loadFolders(restoreView = false) {
     }
     renderFolders();
     $("#connection-label").textContent = "Connected";
+    setTimeout(() => { void refreshFolderListOnly({ forceServer: true }); }, 0);
     if (restoreView) {
       const restoredSearch = readActiveSearchContext();
       if (restoredSearch) {

src/web/js/40-messages-reader.js

@@ -6,10 +6,12 @@ async function loadMessages(reset = false, options = {}) {
   const previousScrollTop = reset && !restoreState && list ? list.scrollTop : null;
   if (reset) {
     state.page = 0;
-    state.messages = [];
+    if (!options.background) {
-    state.selectedMessages.clear();
+      state.messages = [];
-    clearActiveSearchContext();
+      state.selectedMessages.clear();
-    list.innerHTML = `<div class="empty-list">Loading messages…</div>`;
+      clearActiveSearchContext();
+      list.innerHTML = `<div class="empty-list">Loading messages…</div>`;
+    }
   }
   $("#folder-title").textContent = state.folder;
   try {
@@ -22,6 +24,7 @@ async function loadMessages(reset = false, options = {}) {
     let flaggedOnTop = state.currentFolderFlaggedOnTop;
     let folderTotalCount = null;
     let folderUnreadCount = null;
+    let syncing = false;
     let lastLoadedPage = state.page;
     for (const page of pages) {
       const forceRefresh = options.force ? "&refresh=true" : "";
@@ -30,6 +33,7 @@ async function loadMessages(reset = false, options = {}) {
       flaggedOnTop = Boolean(data.flagged_on_top);
       folderTotalCount = Number(data.folder_total_count);
       folderUnreadCount = Number(data.unread_count);
+      syncing = syncing || Boolean(data.syncing);
       loaded.push(...(data.messages || []));
       lastLoadedPage = page;
       if (loaded.length >= totalCount) break;
@@ -38,12 +42,14 @@ async function loadMessages(reset = false, options = {}) {
     state.total = totalCount;
     state.currentFolderFlaggedOnTop = flaggedOnTop;
     state.messages = reset ? loaded : [...state.messages, ...loaded];
-    const folderState = state.folders.find((item) => item.name === state.folder);
+    if (state.folders.some((item) => item.name === state.folder)) {
-    if (folderState) {
+      setFolderCounts(state.folder, folderTotalCount, folderUnreadCount);
-      if (Number.isFinite(folderTotalCount)) folderState.total_count = folderTotalCount;
+    }
-      if (Number.isFinite(folderUnreadCount)) folderState.unread_count = folderUnreadCount;
+    if (syncing) {
-      updateUnreadAppBadge();
+      const pending = Number.isFinite(folderTotalCount) ? Math.max(0, folderTotalCount - state.messages.length) : 0;
-      renderFolders();
+      setImapSyncIndicator(true, state.folder, pending);
+    } else if (state.imapSyncFolder === state.folder) {
+      setImapSyncIndicator(false, null, 0);
     }
     $("#connection-label").textContent = "Connected";
     renderMessages();
@@ -59,28 +65,122 @@ async function loadMessages(reset = false, options = {}) {
   }
 }
 
+function normalizedMessageFlags(value) {
+  const source = Array.isArray(value) ? value : String(value || "").split(/[,\s]+/).filter(Boolean);
+  return [...new Set(source.map((flag) => String(flag).trim()).filter(Boolean))].sort();
+}
+
+function findMessageRow(folder, uid) {
+  return $$(".message-row").find((row) => row.dataset.folder === String(folder) && Number(row.dataset.uid) === Number(uid)) || null;
+}
+
+function updateMessageRowState(folder, uid, flags) {
+  const row = findMessageRow(folder, uid);
+  if (!row) return;
+  const normalized = normalizedMessageFlags(flags);
+  const unread = !normalized.includes("\\Seen");
+  const flagged = normalized.includes("\\Flagged");
+  row.classList.toggle("unread", unread);
+  row.classList.toggle("flagged", flagged);
+  const readButton = row.querySelector(".message-quick-action:not(.message-flag):not(.message-fullscreen-action)");
+  if (readButton) {
+    readButton.title = unread ? "Mark read" : "Mark unread";
+    readButton.setAttribute("aria-label", readButton.title);
+  }
+  const flagButton = row.querySelector(".message-flag");
+  if (flagButton) {
+    flagButton.classList.toggle("active", flagged);
+    flagButton.title = flagged ? "Unflag" : "Flag";
+    flagButton.setAttribute("aria-label", flagButton.title);
+  }
+}
+
+function applyLocalMessageFlags(folder, uid, flags) {
+  const normalized = normalizedMessageFlags(flags);
+  const item = state.messages.find((message) => Number(message.uid) === Number(uid) && (message.folder || state.folder) === folder);
+  if (item) item.flags = normalized.join(" ");
+  if (state.currentDetail?.folder === folder && Number(state.currentDetail?.uid) === Number(uid)) {
+    state.currentDetail.flags = [...normalized];
+    $("#flag-btn")?.classList.toggle("active", normalized.includes("\\Flagged"));
+  }
+  updateMessageRowState(folder, uid, normalized);
+}
+
+function applyOptimisticMessageFlag(folder, uid, flag, add) {
+  const message = state.messages.find((item) => Number(item.uid) === Number(uid) && (item.folder || state.folder) === folder);
+  const detailMatches = state.currentDetail?.folder === folder && Number(state.currentDetail?.uid) === Number(uid);
+  const originalFlags = normalizedMessageFlags(message?.flags ?? (detailMatches ? state.currentDetail.flags : []));
+  const next = new Set(originalFlags);
+  add ? next.add(flag) : next.delete(flag);
+  const optimisticFlags = normalizedMessageFlags([...next]);
+  if (originalFlags.join("\u0000") === optimisticFlags.join("\u0000")) return () => {};
+
+  const folderState = state.folders.find((item) => item.name === folder);
+  const originalTotal = Number(folderState?.total_count);
+  const originalUnread = Number(folderState?.unread_count);
+  let optimisticUnread = originalUnread;
+  if (flag === "\\Seen" && Number.isFinite(originalUnread)) {
+    const wasSeen = originalFlags.includes("\\Seen");
+    const isSeen = optimisticFlags.includes("\\Seen");
+    if (wasSeen !== isSeen) optimisticUnread = Math.max(0, originalUnread + (isSeen ? -1 : 1));
+  }
+
+  applyLocalMessageFlags(folder, uid, optimisticFlags);
+  if (Number.isFinite(originalTotal) && Number.isFinite(optimisticUnread) && optimisticUnread !== originalUnread) {
+    setFolderCounts(folder, originalTotal, optimisticUnread);
+  }
+
+  return () => {
+    const current = state.messages.find((item) => Number(item.uid) === Number(uid) && (item.folder || state.folder) === folder);
+    const currentFlags = normalizedMessageFlags(current?.flags ?? (detailMatches ? state.currentDetail?.flags : []));
+    if (currentFlags.join("\u0000") === optimisticFlags.join("\u0000")) applyLocalMessageFlags(folder, uid, originalFlags);
+    const latestFolder = state.folders.find((item) => item.name === folder);
+    if (Number.isFinite(originalTotal) && Number.isFinite(originalUnread) && Number(latestFolder?.unread_count) === optimisticUnread) {
+      setFolderCounts(folder, originalTotal, originalUnread);
+    }
+  };
+}
+
+function updateActiveMessageRow() {
+  for (const row of $$(".message-row")) {
+    row.classList.toggle(
+      "active",
+      Boolean(state.selected) && row.dataset.folder === state.selected.folder && Number(row.dataset.uid) === Number(state.selected.uid),
+    );
+  }
+}
+
 async function quickUpdateMessageFlag(message, flag, add, successMessage) {
   const folder = message.folder || state.folder;
+  const rollback = applyOptimisticMessageFlag(folder, message.uid, flag, add);
   try {
-    await request(`/messages/${encodeURIComponent(folder)}/${message.uid}/flags`, { method: "PATCH", body: JSON.stringify({ flags: [flag], add }) });
+    const result = await request(`/messages/${encodeURIComponent(folder)}/${message.uid}/flags`, { method: "PATCH", body: JSON.stringify({ flags: [flag], add }) });
-    const flags = new Set(Array.isArray(message.flags) ? message.flags : String(message.flags || "").split(/[,\s]+/).filter(Boolean));
+    const flags = Array.isArray(result.flags) ? result.flags : normalizedMessageFlags(message.flags);
-    add ? flags.add(flag) : flags.delete(flag);
+    if (!Array.isArray(result.flags)) {
-    message.flags = [...flags].join(" ");
+      const next = new Set(flags);
-    if (state.currentDetail?.uid === message.uid && state.currentDetail?.folder === folder) {
+      add ? next.add(flag) : next.delete(flag);
-      const detailFlags = new Set(state.currentDetail.flags || []);
+      applyLocalMessageFlags(folder, message.uid, [...next]);
-      add ? detailFlags.add(flag) : detailFlags.delete(flag);
+    } else {
-      state.currentDetail.flags = [...detailFlags];
+      applyLocalMessageFlags(folder, message.uid, flags);
-      renderMessageDetail(state.currentDetail);
+    }
+    if (Number.isFinite(Number(result.total_count)) && Number.isFinite(Number(result.unread_count))) {
+      setFolderCounts(folder, Number(result.total_count), Number(result.unread_count));
+    }
+    if (flag === "\\Flagged" && state.currentFolderFlaggedOnTop && !state.searchContext && folder === state.folder) {
+      await loadMessages(true, { background: true });
     }
-    if (flag === "\\Flagged" && state.currentFolderFlaggedOnTop && !state.searchContext && folder === state.folder) await loadMessages(true);
-    else renderMessages();
     toast(successMessage, "success");
-  } catch (error) { toast(error.message, "error"); }
+  } catch (error) {
+    rollback();
+    toast(error.message, "error");
+  }
 }
 
 function renderMessages() {
   $("#folder-title").textContent = state.folder;
-  $("#message-count").textContent = `${state.total} ${state.total === 1 ? "message" : "messages"}`;
+  const folderTotal = Number(state.folders.find((folder) => folder.name === state.folder)?.total_count);
+  const displayTotal = !state.searchContext && Number.isFinite(folderTotal) ? folderTotal : state.total;
+  $("#message-count").textContent = `${displayTotal} ${displayTotal === 1 ? "message" : "messages"}`;
   const list = $("#message-list");
   const highlightTerms = activeSearchHighlightTerms();
   list.classList.toggle("selection-mode", state.selectionMode);
@@ -94,6 +194,8 @@ function renderMessages() {
     const checked = state.selectedMessages.has(messageKey(message));
     const active = state.selected?.uid === message.uid && state.selected?.folder === folder;
     const row = el("div", `message-row ${unread ? "unread" : ""} ${flagged ? "flagged" : ""} ${active ? "active" : ""} ${checked ? "selected" : ""}`);
+    row.dataset.folder = folder;
+    row.dataset.uid = String(message.uid);
     row.tabIndex = 0;
     row.setAttribute("role", "button");
     row.setAttribute("aria-label", `${message.from_name || message.from_address || "Unknown"}: ${message.subject || "(no subject)"}`);
@@ -122,13 +224,21 @@ function renderMessages() {
     readButton.title = unread ? "Mark read" : "Mark unread";
     readButton.setAttribute("aria-label", readButton.title);
     readButton.innerHTML = svgIcon("mail");
-    readButton.addEventListener("click", (event) => { event.stopPropagation(); quickUpdateMessageFlag(message, "\\Seen", unread, unread ? "Marked read" : "Marked unread"); });
+    readButton.addEventListener("click", (event) => {
+      event.stopPropagation();
+      const currentUnread = !normalizedMessageFlags(message.flags).includes("\\Seen");
+      quickUpdateMessageFlag(message, "\\Seen", currentUnread, currentUnread ? "Marked read" : "Marked unread");
+    });
     const flagButton = el("button", `message-quick-action message-flag ${flagged ? "active" : ""}`);
     flagButton.type = "button";
     flagButton.title = flagged ? "Unflag" : "Flag";
     flagButton.setAttribute("aria-label", flagButton.title);
     flagButton.innerHTML = svgIcon("star");
-    flagButton.addEventListener("click", (event) => { event.stopPropagation(); quickUpdateMessageFlag(message, "\\Flagged", !flagged, flagged ? "Flag removed" : "Message flagged"); });
+    flagButton.addEventListener("click", (event) => {
+      event.stopPropagation();
+      const currentFlagged = normalizedMessageFlags(message.flags).includes("\\Flagged");
+      quickUpdateMessageFlag(message, "\\Flagged", !currentFlagged, currentFlagged ? "Flag removed" : "Message flagged");
+    });
     const fullscreenButton = el("button", "message-quick-action message-fullscreen-action");
     fullscreenButton.type = "button";
     fullscreenButton.title = "Open full screen";
@@ -281,7 +391,7 @@ async function openMessage(folder, uid) {
   clearTimeout(state.markReadTimer);
   state.markReadTimer = null;
   state.selected = { folder, uid };
-  renderMessages();
+  updateActiveMessageRow();
   updateMessageNavigation();
   $("#reader-empty").classList.add("hidden");
   $("#reader-content").classList.remove("hidden");
@@ -311,16 +421,15 @@ function scheduleMarkRead(detail) {
   const delay = Math.max(0, Number(state.mailPrefs.mark_read_delay_ms || 0));
   const run = async () => {
     if (!state.currentDetail || state.currentDetail.uid !== detail.uid || state.currentDetail.folder !== detail.folder) return;
+    const rollback = applyOptimisticMessageFlag(detail.folder, detail.uid, "\\Seen", true);
     try {
-      await request(`/messages/${encodeURIComponent(detail.folder)}/${detail.uid}/flags`, { method: "PATCH", body: JSON.stringify({ flags: ["\\Seen"], add: true }) });
+      const result = await request(`/messages/${encodeURIComponent(detail.folder)}/${detail.uid}/flags`, { method: "PATCH", body: JSON.stringify({ flags: ["\\Seen"], add: true }) });
-      detail.flags = [...new Set([...(detail.flags || []), "\\Seen"])];
+      const flags = Array.isArray(result.flags) ? result.flags : [...new Set([...(detail.flags || []), "\\Seen"])];
-      const item = state.messages.find((msg) => msg.uid === detail.uid && (msg.folder || state.folder) === detail.folder);
+      applyLocalMessageFlags(detail.folder, detail.uid, flags);
-      if (item) {
+      if (Number.isFinite(Number(result.total_count)) && Number.isFinite(Number(result.unread_count))) {
-        const flags = Array.isArray(item.flags) ? item.flags : String(item.flags || "").split(/[,\s]+/).filter(Boolean);
+        setFolderCounts(detail.folder, Number(result.total_count), Number(result.unread_count));
-        item.flags = [...new Set([...flags, "\\Seen"])].join(" ");
       }
-      renderMessages();
+    } catch (_) { rollback(); }
-    } catch (_) { }
   };
   if (delay === 0) run(); else state.markReadTimer = setTimeout(run, delay);
 }

src/web/js/60-mail-actions-search.js

@@ -2,17 +2,30 @@
 async function updateFlag(flag, add) {
   if (!state.currentDetail) return;
   const detail = state.currentDetail;
-  await request(`/messages/${encodeURIComponent(detail.folder)}/${detail.uid}/flags`, {
+  const rollback = applyOptimisticMessageFlag(detail.folder, detail.uid, flag, add);
-    method: "PATCH",
+  try {
-    body: JSON.stringify({ flags: [flag], add }),
+    const result = await request(`/messages/${encodeURIComponent(detail.folder)}/${detail.uid}/flags`, {
-  });
+      method: "PATCH",
-  const flags = new Set(detail.flags || []);
+      body: JSON.stringify({ flags: [flag], add }),
-  add ? flags.add(flag) : flags.delete(flag);
+    });
-  detail.flags = [...flags];
+    const flags = Array.isArray(result.flags) ? result.flags : normalizedMessageFlags(detail.flags);
-  const item = state.messages.find((msg) => msg.uid === detail.uid && (msg.folder || state.folder) === detail.folder);
+    if (!Array.isArray(result.flags)) {
-  if (item) item.flags = detail.flags.join(" ");
+      const next = new Set(flags);
-  renderMessages();
+      add ? next.add(flag) : next.delete(flag);
-  renderMessageDetail(detail);
+      applyLocalMessageFlags(detail.folder, detail.uid, [...next]);
+    } else {
+      applyLocalMessageFlags(detail.folder, detail.uid, flags);
+    }
+    if (Number.isFinite(Number(result.total_count)) && Number.isFinite(Number(result.unread_count))) {
+      setFolderCounts(detail.folder, Number(result.total_count), Number(result.unread_count));
+    }
+    if (flag === "\\Flagged" && state.currentFolderFlaggedOnTop && !state.searchContext && detail.folder === state.folder) {
+      await loadMessages(true, { background: true });
+    }
+  } catch (error) {
+    rollback();
+    throw error;
+  }
 }
 
 async function toggleUnread() {
@@ -231,7 +244,23 @@ async function performBulk(action, targetFolder = null) {
       if (action === "read" || action === "unread" || action === "flag" || action === "unflag") {
         const flag = action === "read" || action === "unread" ? "\\Seen" : "\\Flagged";
         const add = action === "read" || action === "flag";
-        await request(`/messages/${encodeURIComponent(folder)}/${message.uid}/flags`, { method: "PATCH", body: JSON.stringify({ flags: [flag], add }) });
+        const rollback = applyOptimisticMessageFlag(folder, message.uid, flag, add);
+        let result;
+        try {
+          result = await request(`/messages/${encodeURIComponent(folder)}/${message.uid}/flags`, { method: "PATCH", body: JSON.stringify({ flags: [flag], add }) });
+        } catch (error) {
+          rollback();
+          throw error;
+        }
+        const nextFlags = Array.isArray(result?.flags) ? result.flags : (() => {
+          const flags = new Set(normalizedMessageFlags(message.flags));
+          add ? flags.add(flag) : flags.delete(flag);
+          return [...flags];
+        })();
+        applyLocalMessageFlags(folder, message.uid, nextFlags);
+        if (Number.isFinite(Number(result?.total_count)) && Number.isFinite(Number(result?.unread_count))) {
+          setFolderCounts(folder, Number(result.total_count), Number(result.unread_count));
+        }
       } else if (action === "move" || action === "archive" || action === "junk" || action === "delete") {
         let destination = targetFolder;
         if (action === "archive") destination = detectSpecialFolder("archive");
@@ -252,8 +281,17 @@ async function performBulk(action, targetFolder = null) {
     }
     state.selectedMessages.clear();
     state.searchAllResults = null;
-    await refreshFolderListOnly();
+    const flagsOnly = ["read", "unread", "flag", "unflag"].includes(action);
-    await refreshCurrentMessageView();
+    const orderingChanged = ["flag", "unflag"].includes(action) && state.currentFolderFlaggedOnTop && !state.searchContext;
+    if (!flagsOnly) {
+      await refreshFolderListOnly({ forceServer: true });
+      await refreshCurrentMessageView();
+    } else if (state.searchContext || orderingChanged) {
+      await refreshCurrentMessageView();
+    } else {
+      renderBulkToolbar();
+      updateUnreadAppBadge();
+    }
     const bulkMessages = { junk: bulkJunkToInbox ? tr("marked_not_spam", "Marked as not spam") : tr("marked_spam", "Marked as spam"), archive: "Archived", read: "Marked read", unread: "Marked unread", flag: "Flagged", unflag: "Unflagged", delete: "Deleted", move: "Moved", copy: "Copied" };
     const undoAction = movedOperations > 0 && undoMoves.length === movedOperations ? bulkMoveUndoAction(undoMoves) : null;
     toast(`${bulkMessages[action] || "Updated"}: ${completed} message${completed === 1 ? "" : "s"}`, "success", undoAction ? 10000 : null, undoAction);
@@ -264,12 +302,28 @@ async function performBulk(action, targetFolder = null) {
   }
 }
 
-async function refreshFolderListOnly() {
+async function refreshFolderListOnly(options = {}) {
   try {
-    const data = await request("/folders", { method: "GET" });
+    const suffix = options.forceServer ? "?refresh=true" : "";
-    state.folders = data.folders || [];
+    const data = await request(`/folders${suffix}`, { method: "GET" });
+    const nextFolders = data.folders || [];
+    setImapSyncInventoryPending(data.pending_sync_count);
+    setIndexingIndicator(state.indexingActive, data.pending_index_count);
+    const previousNames = state.folders.map((folder) => folder.name).join("\u0000");
+    const nextNames = nextFolders.map((folder) => folder.name).join("\u0000");
+    if (previousNames !== nextNames || state.folders.length !== nextFolders.length) {
+      state.folders = nextFolders;
+      renderFolders();
+    } else {
+      const byName = new Map(nextFolders.map((folder) => [folder.name, folder]));
+      for (const folder of state.folders) {
+        const fresh = byName.get(folder.name);
+        if (!fresh) continue;
+        Object.assign(folder, fresh);
+        updateFolderCounter(folder);
+      }
+    }
     updateUnreadAppBadge();
-    renderFolders();
   } catch (_) { }
 }
 
@@ -621,9 +675,22 @@ function showFolderProperties(folder) {
 
 async function markFolderAllRead(name) {
   try {
-    await request(`/folders/${encodeURIComponent(name)}/mark-all-read`, { method: "POST", body: "{}" });
+    const result = await request(`/folders/${encodeURIComponent(name)}/mark-all-read`, { method: "POST", body: "{}" });
-    if (state.folder === name) await loadMessages(true);
+    if (state.folder === name) {
-    await refreshFolderListOnly();
+      const throughUid = Number(result?.through_uid);
+      for (const message of state.messages) {
+        if (Number.isFinite(throughUid) && Number(message.uid) > throughUid) continue;
+        const flags = normalizedMessageFlags(message.flags);
+        if (!flags.includes("\\Seen")) flags.push("\\Seen");
+        applyLocalMessageFlags(name, message.uid, flags);
+      }
+    }
+    const folder = state.folders.find((item) => item.name === name);
+    setFolderCounts(
+      name,
+      Number.isFinite(Number(result?.total_count)) ? Number(result.total_count) : Number(folder?.total_count || 0),
+      Number.isFinite(Number(result?.unread_count)) ? Number(result.unread_count) : 0,
+    );
     toast("All messages marked read");
   } catch (error) { toast(error.message, "error"); }
 }

src/web/js/80-settings-realtime.js

@@ -160,17 +160,48 @@ function playNotificationSound() {
   } catch (_) { }
 }
 
-function setIndexingIndicator(active, pending = 0) {
+function renderSyncActivityIndicator() {
-  state.indexingActive = Boolean(active);
   const indicator = $("#indexing-indicator");
   if (!indicator) return;
-  indicator.classList.toggle("hidden", !state.indexingActive);
+  const busy = Boolean(state.indexingActive || state.imapSyncActive);
-  const count = Math.max(0, Number(pending) || 0);
+  indicator.classList.toggle("hidden", !busy);
-  const label = count > 0 ? `Indexing messages (${count} pending)` : "Indexing messages";
+  indicator.classList.toggle("active", busy);
+  const parts = [];
+  if (state.imapSyncActive || state.imapSyncPending > 0) {
+    const folder = state.imapSyncFolder ? ` · ${state.imapSyncFolder}` : "";
+    const pending = state.imapSyncPending > 0 ? ` · ${state.imapSyncPending} headers pending in task` : "";
+    parts.push(`IMAP synchronization${folder}${pending}`);
+  }
+  if (state.imapSyncInventoryPending > 0) {
+    parts.push(`IMAP cache incomplete · ${state.imapSyncInventoryPending} message headers not cached yet`);
+  }
+  if (state.indexingActive || state.indexingPending > 0) {
+    const pending = state.indexingPending > 0 ? ` · ${state.indexingPending} messages pending` : "";
+    parts.push(`Search indexing${pending}`);
+  }
+  const label = parts.join(" | ") || "Mail synchronization";
   indicator.title = label;
   indicator.setAttribute("aria-label", label);
 }
 
+function setIndexingIndicator(active, pending = 0) {
+  state.indexingActive = Boolean(active);
+  state.indexingPending = Math.max(0, Number(pending) || 0);
+  renderSyncActivityIndicator();
+}
+
+function setImapSyncIndicator(active, folder = null, pending = 0) {
+  state.imapSyncActive = Boolean(active);
+  state.imapSyncFolder = folder || null;
+  state.imapSyncPending = Math.max(0, Number(pending) || 0);
+  renderSyncActivityIndicator();
+}
+
+function setImapSyncInventoryPending(pending = 0) {
+  state.imapSyncInventoryPending = Math.max(0, Number(pending) || 0);
+  renderSyncActivityIndicator();
+}
+
 function syncRealtimeWatchedFolder(force = false) {
   const socket = state.ws;
   if (!socket || socket.readyState !== WebSocket.OPEN || !state.accountId || !state.folder) return;
@@ -296,23 +327,62 @@ function realtimeEventKey(payload) {
 function isDuplicateRealtimeEvent(payload) {
   const now = Date.now();
   for (const [key, seenAt] of state.realtimeSeenEvents) if (now - seenAt > 10000) state.realtimeSeenEvents.delete(key);
+
+  // Server websocket envelopes carry a unique eventId. When present it is the
+  // only safe deduplication key: state can legitimately cycle A -> B -> A in
+  // under a second (for example unread 1 -> 0 -> 1). Fingerprint-based
+  // deduplication would incorrectly drop the second A and leave stale UI.
+  if (payload.eventId) {
+    const idKey = `id:${payload.eventId}`;
+    const duplicate = state.realtimeSeenEvents.has(idKey);
+    state.realtimeSeenEvents.set(idKey, now);
+    return duplicate;
+  }
+
+  // Fallback for legacy/nonstandard envelopes without eventId.
   const event = payload.event || {};
   const fingerprint = `${payload.accountId || ""}|${event.type || ""}|${JSON.stringify(event.data || {})}`;
-  const idKey = payload.eventId ? `id:${payload.eventId}` : null;
   const fingerprintKey = `event:${fingerprint}`;
-  const duplicate = Boolean((idKey && state.realtimeSeenEvents.has(idKey)) || (state.realtimeSeenEvents.get(fingerprintKey) && now - state.realtimeSeenEvents.get(fingerprintKey) < 1500));
+  const seenAt = state.realtimeSeenEvents.get(fingerprintKey);
-  if (idKey) state.realtimeSeenEvents.set(idKey, now);
+  const duplicate = Boolean(seenAt && now - seenAt < 1500);
   state.realtimeSeenEvents.set(fingerprintKey, now);
   return duplicate;
 }
 
+function applyRealtimeFolderStatus(data) {
+  if (!data?.folder) return;
+  setFolderCounts(data.folder, Number(data.total_count), Number(data.unread_count));
+}
+
+function applyRealtimeFlagChanges(data) {
+  if (!data?.folder) return false;
+  const changes = Array.isArray(data.changes) ? data.changes : [];
+  for (const change of changes) {
+    if (!Number.isFinite(Number(change?.uid))) continue;
+    applyLocalMessageFlags(data.folder, Number(change.uid), change.flags || []);
+  }
+  return changes.length > 0;
+}
+
+function applyRealtimeFolderAllRead(data) {
+  const folder = data?.folder;
+  if (!folder || folder !== state.folder) return;
+  const throughUid = Number(data?.through_uid);
+  for (const message of state.messages) {
+    if (Number.isFinite(throughUid) && Number(message.uid) > throughUid) continue;
+    const flags = normalizedMessageFlags(message.flags);
+    if (!flags.includes("\\Seen")) flags.push("\\Seen");
+    applyLocalMessageFlags(folder, message.uid, flags);
+  }
+}
+
 async function resyncRealtimeState() {
   if (!state.accountId) return;
   if (state.realtimeSyncPromise) return state.realtimeSyncPromise;
   state.realtimeSyncPromise = (async () => {
-    await refreshFolderListOnly();
+    await refreshFolderListOnly({ forceServer: true });
     if (state.searchContext) await runSearch(new URLSearchParams(state.searchContext.params), state.searchContext.label, { restoreScrollTop: state.searchContext.scrollTop });
-    else await loadMessages(true);
+    else await loadMessages(true, { background: true });
   })().catch(() => { }).finally(() => { state.realtimeSyncPromise = null; });
   return state.realtimeSyncPromise;
 }
@@ -323,13 +393,16 @@ function scheduleRealtimeRefresh(event, accountId) {
   clearTimeout(state.realtimeRefreshTimer);
   state.realtimeRefreshTimer = setTimeout(async () => {
     const events = state.realtimeRefreshEvents.splice(0);
-    const refreshCurrent = events.some((item) => item.type === "FolderUpdated" || (["NewMessages", "FlagsChanged"].includes(item.type) && item.data?.folder === state.folder));
+    const folderTreeChanged = events.some((item) => item.type === "FolderUpdated");
-    const tasks = [refreshFolderListOnly()];
+    const newInCurrent = events.some((item) => item.type === "NewMessages" && item.data?.folder === state.folder);
-    if (refreshCurrent) {
+    const structuralFlagsInCurrent = events.some((item) => item.type === "FlagsChanged" && item.data?.folder === state.folder && !(item.data?.changes || []).length);
+    const tasks = [];
+    if (folderTreeChanged) tasks.push(refreshFolderListOnly());
+    if (folderTreeChanged || newInCurrent || structuralFlagsInCurrent) {
       if (state.searchContext) tasks.push(runSearch(new URLSearchParams(state.searchContext.params), state.searchContext.label, { restoreScrollTop: state.searchContext.scrollTop }));
-      else tasks.push(loadMessages(true));
+      else tasks.push(loadMessages(true, { background: true }));
     }
-    await Promise.all(tasks);
+    if (tasks.length) await Promise.all(tasks);
   }, 80);
 }
 
@@ -402,10 +475,29 @@ function connectRealtime() {
           notifyNewMail(data, payload.accountId);
         }
       }
-      if (event.type === "IndexingStatus" && payload.accountId === state.accountId) {
+      if (payload.accountId === state.accountId) {
-        setIndexingIndicator(Boolean(event.data?.active), event.data?.pending);
+        if (event.type === "FolderStatus") applyRealtimeFolderStatus(event.data || {});
+        if (event.type === "FlagsChanged") {
+          const patched = applyRealtimeFlagChanges(event.data || {});
+          if (!patched) scheduleRealtimeRefresh(event, payload.accountId);
+        }
+        if (event.type === "FolderAllRead") applyRealtimeFolderAllRead(event.data || {});
+        if (event.type === "IndexingStatus") setIndexingIndicator(Boolean(event.data?.active), event.data?.pending);
+        if (event.type === "SyncStatus") {
+          const wasActive = state.imapSyncActive;
+          const syncFolder = event.data?.folder || null;
+          const active = Boolean(event.data?.active);
+          setImapSyncIndicator(active, syncFolder, event.data?.pending);
+          const folderState = state.folders.find((folder) => folder.name === syncFolder);
+          const serverTotal = Number(folderState?.total_count);
+          const syncCompletedForCurrentFolder = wasActive && !active && syncFolder === state.folder;
+          if (syncCompletedForCurrentFolder && !state.searchContext && Number.isFinite(serverTotal) && state.total < serverTotal) {
+            void loadMessages(true, { background: true });
+          }
+        }
+        if (event.type === "SyncInventory") setImapSyncInventoryPending(event.data?.pending);
       }
-      if (["NewMessages", "FlagsChanged", "FolderUpdated"].includes(event.type)) scheduleRealtimeRefresh(event, payload.accountId);
+      if (["NewMessages", "FolderUpdated"].includes(event.type)) scheduleRealtimeRefresh(event, payload.accountId);
     } catch (error) { console.warn("Invalid realtime event", error); }
   };
   socket.onclose = () => {
@@ -413,6 +505,7 @@ function connectRealtime() {
     state.ws = null;
     state.realtimeWatchedFolder = null;
     setIndexingIndicator(false);
+    setImapSyncIndicator(false, null, 0);
     clearInterval(state.wsWatchdogTimer);
     state.wsWatchdogTimer = null;
     scheduleRealtimeReconnect();
@@ -435,6 +528,7 @@ function disconnectRealtime() {
   state.wsLastHeartbeatAt = 0;
   state.realtimeWatchedFolder = null;
   setIndexingIndicator(false);
+  setImapSyncIndicator(false, null, 0);
   const socket = state.ws;
   state.ws = null;
   if (socket && socket.readyState < WebSocket.CLOSING) socket.close(1000, "Client disconnect");
@@ -516,7 +610,8 @@ async function loadDiagnostics() {
   try {
     const info = await request("/diagnostics/search", { method: "GET" });
     searchStatus.textContent = "Ready";
-    $("#diagnostic-search-summary").textContent = `${info.indexedDocuments} indexed · ${info.cachedMessages} cached messages · ${info.cachedBodies} cached bodies${info.excludedMessages ? ` · ${info.excludedMessages} excluded` : ""}`;
+    const bodyCacheState = info.deepIndexEnabled ? "body cache enabled" : "body cache disabled";
+    $("#diagnostic-search-summary").textContent = `${info.indexedDocuments} indexed · ${info.cachedMessages} cached messages · ${info.cachedBodies} cached bodies · ${bodyCacheState}${info.excludedMessages ? ` · ${info.excludedMessages} excluded` : ""}`;
   } catch (error) {
     searchStatus.textContent = "Unavailable";
     $("#diagnostic-search-summary").textContent = error.message;
@@ -542,6 +637,7 @@ async function rebuildSearchIndex() {
   const button = $("#diagnostic-search-rebuild");
   if (!await appConfirm("Rebuild the search index from the local message cache?", { title: "Rebuild search index", confirmLabel: "Rebuild" })) return;
   button.disabled = true;
+  setIndexingIndicator(true, 0);
   try {
     const result = await request("/diagnostics/search/rebuild", { method: "POST", body: "{}" });
     toast(`Search index rebuilt: ${result.indexedDocuments} messages`);
@@ -549,6 +645,7 @@ async function rebuildSearchIndex() {
   } catch (error) {
     toast(error.message, "error");
   } finally {
+    setIndexingIndicator(false, 0);
     button.disabled = false;
   }
 }

src/web/js/95-bindings-boot.js

@@ -237,7 +237,7 @@ function bindEvents() {
     const button = $("#refresh-btn");
     setBusy(button, true);
     try {
-      const folderRefresh = refreshFolderListOnly();
+      const folderRefresh = refreshFolderListOnly({ forceServer: true });
       if (state.searchContext) {
         await Promise.all([folderRefresh, runSearch(new URLSearchParams(state.searchContext.params), state.searchContext.label, { restoreScrollTop: state.searchContext.scrollTop })]);
       } else {
@@ -266,7 +266,7 @@ function bindEvents() {
     disconnectRealtime();
     connectRealtime();
     if (state.accounts.length) {
-      await refreshFolderListOnly();
+      await refreshFolderListOnly({ forceServer: true });
       if (state.searchContext) await runSearch(new URLSearchParams(state.searchContext.params), state.searchContext.label, { restoreScrollTop: state.searchContext.scrollTop });
       else await loadMessages(true);
     }
@@ -559,7 +559,7 @@ async function boot() {
   await loadAuthPolicy();
   const authenticated = await loadAccounts();
   if (authenticated) {
-    await loadPreferences(); await loadMailPreferences(); if (state.authPolicy.pgpEnabled !== false) await loadOpenPgp(); else setOpenPgpAvailability(false); await loadIdentities(); await loadResponseTemplates(); await loadFolders(true); await loadSpecialFolders(); await loadQuota(); await loadTags(); await loadNotificationPreferences(); await loadTrustedSenders(); startCalendarReminderWatcher(); connectRealtime();
+    await loadSessionPolicy(); await loadPreferences(); await loadMailPreferences(); if (state.authPolicy.pgpEnabled !== false) await loadOpenPgp(); else setOpenPgpAvailability(false); await loadIdentities(); await loadResponseTemplates(); await loadFolders(true); await loadSpecialFolders(); await loadQuota(); await loadTags(); await loadNotificationPreferences(); await loadTrustedSenders(); startCalendarReminderWatcher(); connectRealtime();
     const params = new URLSearchParams(location.search);
     const folder = params.get("mail_folder");
     const uid = Number(params.get("mail_uid"));

src/web/theme-bootstrap.js

@@ -0,0 +1,8 @@
+(() => {
+  const root = document.documentElement;
+  const configured = root.dataset.defaultTheme || "system";
+  root.dataset.theme = configured === "system"
+    ? (matchMedia("(prefers-color-scheme: light)").matches ? "light" : "dark")
+    : configured;
+  root.dataset.interfaceSkin = root.dataset.defaultInterfaceSkin || "rustbox";
+})();