feat(email): add thread_id field to EmailAddedToFolder

src/modules/cache/imap/sync/flow.rs

@@ -774,6 +774,7 @@ async fn process_email_added_events(
 ) -> RustMailerResult<()> {
     for fetch in fetches {
         let envelope = extract_envelope(fetch, account.id, &remote.name)?;
+        let thread_id = envelope.compute_thread_id();
         let message_content = match envelope.body_meta {
             Some(sections) => {
                 let request = MessageContentRequest {
@@ -823,6 +824,7 @@ async fn process_email_added_events(
                             .attachments
                             .as_ref()
                             .map(|atts| atts.iter().cloned().map(Attachment::from).collect()),
+                        thread_id,
                     }),
                 ),
             ))

src/modules/hook/events/mod.rs

@@ -185,6 +185,7 @@ impl RustMailerEvent {
                     html: Some(String::from("<p>Welcome to use rustmailer!</p>")),
                 },
                 thread_name: Some("Meeting Thread".into()),
+                thread_id: id!(64),
                 reply_to: Some(vec![addr("reply@example.com")]),
                 to: Some(vec![addr("recipient@example.com")]),
                 attachments: Some(vec![Attachment {

src/modules/hook/events/payload.rs

@@ -44,6 +44,9 @@ pub struct EmailAddedToFolder {
     pub subject: Option<String>,
     /// Content of the email, including body and related metadata.
     pub message: MessageContent,
+    /// The identifier of the thread this email belongs to.
+    /// This is computed based on `in_reply_to` / `references` / `message_id`.
+    pub thread_id: u64,
     /// Optional name of the thread to which the email belongs.
     pub thread_name: Option<String>,
     /// Optional list of reply-to addresses for the email.