IMAP responses to APPEND and EXPUNGE should include HIGHESTMODSEQ when CONDSTORE is enabled.

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to this project will be documented in this file. This projec
 
 ### Fixed
 - IMAP command `SEARCH <seqnum>` is using UIDs rather than sequence numbers.
+- IMAP responses to `APPEND` and `EXPUNGE` should include `HIGHESTMODSEQ` when `CONDSTORE` is enabled.
 
 ## [0.5.1] - 2024-01-02
 

crates/imap-proto/src/protocol/select.rs

@@ -41,6 +41,9 @@ pub struct QResync {
     pub seq_match: Option<(Sequence, Sequence)>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct HighestModSeq(u64);
+
 #[derive(Debug, Clone)]
 pub struct Response {
     pub mailbox: ListItem,
@@ -51,7 +54,7 @@ pub struct Response {
     pub uid_next: u32,
     pub is_rev2: bool,
     pub closed_previous: bool,
-    pub highest_modseq: Option<u64>,
+    pub highest_modseq: Option<HighestModSeq>,
     pub mailbox_id: String,
 }
 
@@ -100,9 +103,7 @@ impl ImapResponse for Response {
         buf.extend_from_slice(self.uid_next.to_string().as_bytes());
         buf.extend_from_slice(b"] Next predicted UID\r\n");
         if let Some(highest_modseq) = self.highest_modseq {
-            buf.extend_from_slice(b"* OK [HIGHESTMODSEQ ");
-            buf.extend_from_slice(highest_modseq.to_string().as_bytes());
-            buf.extend_from_slice(b"] Highest Modseq\r\n");
+            highest_modseq.serialize(&mut buf);
         }
         buf.extend_from_slice(b"* OK [MAILBOXID (");
         buf.extend_from_slice(self.mailbox_id.as_bytes());
@@ -111,6 +112,24 @@ impl ImapResponse for Response {
     }
 }
 
+impl HighestModSeq {
+    pub fn new(modseq: u64) -> Self {
+        Self(modseq)
+    }
+
+    pub fn serialize(&self, buf: &mut Vec<u8>) {
+        buf.extend_from_slice(b"* OK [HIGHESTMODSEQ ");
+        buf.extend_from_slice(self.0.to_string().as_bytes());
+        buf.extend_from_slice(b"] Highest Modseq\r\n");
+    }
+
+    pub fn into_bytes(self) -> Vec<u8> {
+        let mut buf = Vec::with_capacity(40);
+        self.serialize(&mut buf);
+        buf
+    }
+}
+
 impl Exists {
     pub fn serialize(&self, buf: &mut Vec<u8>) {
         buf.extend_from_slice(b"* ");
@@ -129,6 +148,8 @@ impl Exists {
 mod tests {
     use crate::protocol::{list::ListItem, ImapResponse};
 
+    use super::HighestModSeq;
+
     #[test]
     fn serialize_select() {
         for (mut response, _tag, expected_v2, expected_v1) in [
@@ -142,7 +163,7 @@ mod tests {
                     uid_next: 4392,
                     closed_previous: false,
                     is_rev2: true,
-                    highest_modseq: 100.into(),
+                    highest_modseq: HighestModSeq::new(100).into(),
                     mailbox_id: "abc".into(),
                 },
                 "A142",

crates/imap/src/op/append.rs

@@ -24,7 +24,9 @@
 use std::sync::Arc;
 
 use imap_proto::{
-    protocol::append::Arguments, receiver::Request, Command, ResponseCode, StatusResponse,
+    protocol::{append::Arguments, select::HighestModSeq},
+    receiver::Request,
+    Command, ResponseCode, StatusResponse,
 };
 
 use jmap::email::ingest::IngestEmail;
@@ -34,6 +36,8 @@ use tokio::io::AsyncRead;
 
 use crate::core::{MailboxId, SelectedMailbox, Session, SessionData};
 
+use super::ToModSeq;
+
 impl<T: AsyncRead> Session<T> {
     pub async fn handle_append(&mut self, request: Request<Command>) -> crate::OpResult {
         match request.parse_append(self.version) {
@@ -167,12 +171,20 @@ impl SessionData {
                 .await;
         }
 
-        if !created_ids.is_empty() && self.imap.enable_uidplus {
+        if !created_ids.is_empty() {
             let (uids, uid_validity) = match selected_mailbox {
                 Some(selected_mailbox) if selected_mailbox.id == mailbox => {
-                    self.write_mailbox_changes(&selected_mailbox, is_qresync)
+                    let modseq = self
+                        .write_mailbox_changes(&selected_mailbox, is_qresync)
                         .await
                         .map_err(|r| r.with_tag(&arguments.tag))?;
+
+                    // Write updated modseq
+                    if is_qresync {
+                        self.write_bytes(HighestModSeq::new(modseq.to_modseq()).into_bytes())
+                            .await;
+                    }
+
                     let mailbox = selected_mailbox.state.lock();
                     (
                         created_ids
@@ -184,7 +196,7 @@ impl SessionData {
                     )
                 }
 
-                _ => {
+                _ if self.imap.enable_uidplus => {
                     let mailbox = self
                         .fetch_messages(&mailbox)
                         .await
@@ -198,6 +210,7 @@ impl SessionData {
                         mailbox.uid_validity,
                     )
                 }
+                _ => (vec![], 0),
             };
             if !uids.is_empty() {
                 response = response.with_code(ResponseCode::AppendUid { uid_validity, uids });

crates/imap/src/op/expunge.rs

@@ -43,6 +43,8 @@ use tokio::io::AsyncRead;
 
 use crate::core::{ImapId, SavedSearch, SelectedMailbox, Session, SessionData};
 
+use super::ToModSeq;
+
 impl<T: AsyncRead> Session<T> {
     pub async fn handle_expunge(
         &mut self,
@@ -108,13 +110,17 @@ impl<T: AsyncRead> Session<T> {
 
         // Synchronize messages
         match data.write_mailbox_changes(&mailbox, self.is_qresync).await {
-            Ok(_) => {
-                self.write_bytes(
-                    StatusResponse::completed(Command::Expunge(is_uid))
-                        .with_tag(request.tag)
-                        .into_bytes(),
-                )
-                .await
+            Ok(modseq) => {
+                let mut response =
+                    StatusResponse::completed(Command::Expunge(is_uid)).with_tag(request.tag);
+
+                if self.is_condstore {
+                    response = response.with_code(ResponseCode::HighestModseq {
+                        modseq: modseq.to_modseq(),
+                    });
+                }
+
+                self.write_bytes(response.into_bytes()).await
             }
             Err(response) => {
                 self.write_bytes(response.with_tag(request.tag).into_bytes())

crates/imap/src/op/select.rs

@@ -24,7 +24,12 @@
 use std::sync::Arc;
 
 use imap_proto::{
-    protocol::{fetch, list::ListItem, select::Response, ImapResponse, Sequence},
+    protocol::{
+        fetch,
+        list::ListItem,
+        select::{HighestModSeq, Response},
+        ImapResponse, Sequence,
+    },
     receiver::Request,
     Command, ResponseCode, StatusResponse,
 };
@@ -64,7 +69,7 @@ impl<T: AsyncRead> Session<T> {
                             let uid_next = state.uid_next;
                             let total_messages = state.total_messages;
                             let highest_modseq = if is_condstore {
-                                state.modseq.to_modseq().into()
+                                HighestModSeq::new(state.modseq.to_modseq()).into()
                             } else {
                                 None
                             };

resources/config/imap/settings.toml

@@ -19,7 +19,7 @@ idle = "30m"
 
 [imap.rate-limit]
 requests = "2000/1m"
-concurrent = 4
+concurrent = 6
 
 [imap.protocol]
 uidplus = false