v0.2.20

src/imap/client.rs

@@ -268,6 +268,22 @@ pub struct RealImapClient {
     pool: super::pool::ConnectionPool,
 }
 
+fn resolve_message_date(
+    envelope_date: Option<String>,
+    internal_date: Option<String>,
+) -> Option<String> {
+    envelope_date
+        .and_then(|value| {
+            let trimmed = value.trim();
+            if trimmed.is_empty() || mail_parser::DateTime::parse_rfc822(trimmed).is_none() {
+                None
+            } else {
+                Some(trimmed.to_string())
+            }
+        })
+        .or_else(|| internal_date.filter(|value| !value.trim().is_empty()))
+}
+
 #[async_trait]
 impl ImapClient for RealImapClient {
     async fn capabilities(&self, creds: &ImapCredentials) -> Result<Vec<String>, ImapError> {
@@ -380,7 +396,7 @@ impl ImapClient for RealImapClient {
             let mut fetch_stream = session
                 .uid_fetch(
                     uid_range,
-                    "(UID ENVELOPE FLAGS BODYSTRUCTURE RFC822.SIZE BODY.PEEK[HEADER.FIELDS (Message-ID In-Reply-To References Content-Class x-ms-exchange-generated-message-class)])",
+                    "(UID ENVELOPE INTERNALDATE FLAGS BODYSTRUCTURE RFC822.SIZE BODY.PEEK[HEADER.FIELDS (Message-ID In-Reply-To References Content-Class x-ms-exchange-generated-message-class)])",
                 )
                 .await
                 .map_err(map_imap_error)?;
@@ -405,6 +421,7 @@ impl ImapClient for RealImapClient {
                 let raw_header_bytes = fetch.header();
                 let parsed_threading = raw_header_bytes
                     .and_then(|raw| mail_parser::MessageParser::default().parse(raw));
+                let internal_date = fetch.internal_date().map(|value| value.to_rfc2822());
 
                 let (subject, from, to, cc, date) = if let Some(env) = fetch.envelope() {
                     let subject = env.subject.as_ref().map(|b| decode_header_bytes(b));
@@ -427,11 +444,12 @@ impl ImapClient for RealImapClient {
                         .map(|addrs| addrs.iter().map(imap_address_to_email).collect())
                         .unwrap_or_default();
 
-                    let date = env
+                    let envelope_date = env
                         .date
                         .as_ref()
                         .and_then(|b| std::str::from_utf8(b).ok())
-                        .map(|s| s.to_string());
+                        .map(str::to_string);
+                    let date = resolve_message_date(envelope_date, internal_date.clone());
 
                     (subject, from, to, cc, date)
                 } else {
@@ -440,7 +458,13 @@ impl ImapClient for RealImapClient {
                         folder = %folder,
                         "ENVELOPE missing for message, headers will be empty until body is fetched"
                     );
-                    (None, vec![], vec![], vec![], None)
+                    (
+                        None,
+                        vec![],
+                        vec![],
+                        vec![],
+                        resolve_message_date(None, internal_date.clone()),
+                    )
                 };
 
                 let message_id = parsed_threading
@@ -1337,3 +1361,38 @@ impl ImapClient for RealImapClient {
         Ok(supported)
     }
 }
+
+#[cfg(test)]
+mod date_resolution_tests {
+    use super::resolve_message_date;
+
+    #[test]
+    fn uses_internal_date_when_message_date_is_missing() {
+        assert_eq!(
+            resolve_message_date(None, Some("Tue, 3 Nov 2026 14:38:39 +0100".to_string())),
+            Some("Tue, 3 Nov 2026 14:38:39 +0100".to_string())
+        );
+    }
+
+    #[test]
+    fn uses_internal_date_when_message_date_is_invalid() {
+        assert_eq!(
+            resolve_message_date(
+                Some("not-a-date".to_string()),
+                Some("Tue, 3 Nov 2026 14:38:39 +0100".to_string())
+            ),
+            Some("Tue, 3 Nov 2026 14:38:39 +0100".to_string())
+        );
+    }
+
+    #[test]
+    fn keeps_valid_message_date() {
+        assert_eq!(
+            resolve_message_date(
+                Some("Mon, 2 Nov 2026 10:00:00 +0100".to_string()),
+                Some("Tue, 3 Nov 2026 14:38:39 +0100".to_string())
+            ),
+            Some("Mon, 2 Nov 2026 10:00:00 +0100".to_string())
+        );
+    }
+}