crates/smtp/src/inbound/milter/message.rs

@@ -2,6 +2,8 @@
  * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ *
+ * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
 use super::{Action, Error, Macros, Modification};
@@ -77,23 +79,36 @@ impl<T: SessionStream> Session<T> {
                     }
                 }
                 Err(Rejection::Action(action)) => {
-                    trc::event!(
-                        Milter(match &action {
-                            Action::Discard => MilterEvent::ActionDiscard,
-                            Action::Reject => MilterEvent::ActionReject,
-                            Action::TempFail => MilterEvent::ActionTempFail,
-                            Action::ReplyCode { .. } => {
-                                MilterEvent::ActionReplyCode
-                            }
-                            Action::Shutdown => MilterEvent::ActionShutdown,
-                            Action::ConnectionFailure => MilterEvent::ActionConnectionFailure,
-                            Action::Accept | Action::Continue => unreachable!(),
-                        }),
-                        SpanId = self.data.session_id,
-                        QueueId = queue_id,
-                        Id = milter.id.to_string(),
-                        Elapsed = time.elapsed(),
-                    );
+                    if let Action::ReplyCode { code, text } = &action {
+                        trc::event!(
+                            Milter(MilterEvent::ActionReplyCode),
+                            SpanId = self.data.session_id,
+                            QueueId = queue_id,
+                            Id = milter.id.to_string(),
+                            Code = std::str::from_utf8(code)
+                                .ok()
+                                .and_then(|code| code.parse::<u16>().ok()),
+                            Details = text.trim_end().to_string(),
+                            Elapsed = time.elapsed(),
+                        );
+                    } else {
+                        trc::event!(
+                            Milter(match &action {
+                                Action::Discard => MilterEvent::ActionDiscard,
+                                Action::Reject => MilterEvent::ActionReject,
+                                Action::TempFail => MilterEvent::ActionTempFail,
+                                Action::Shutdown => MilterEvent::ActionShutdown,
+                                Action::ConnectionFailure => MilterEvent::ActionConnectionFailure,
+                                Action::ReplyCode { .. } | Action::Accept | Action::Continue => {
+                                    unreachable!()
+                                }
+                            }),
+                            SpanId = self.data.session_id,
+                            QueueId = queue_id,
+                            Id = milter.id.to_string(),
+                            Elapsed = time.elapsed(),
+                        );
+                    }
 
                     return Err(match action {
                         Action::Discard => FilterResponse::accept(),

tests/src/smtp/inbound/milter.rs

@@ -52,6 +52,7 @@ use tokio::{
     net::{TcpListener, TcpStream},
     sync::watch,
 };
+use trc::{Collector, EventType, Key, MilterEvent, ipc::subscriber::SubscriberBuilder};
 
 #[derive(Debug, Deserialize)]
 struct HeaderTest {
@@ -145,17 +146,51 @@ async fn milter_session() {
         .await;
     test.assert_no_events();
 
-    // Test reply code
+    // Capture the actual event emitted by the SMTP session, not a reconstructed event.
+    let subscriber_id = "smtp-milter-reply-code".to_string();
+    let subscriber = SubscriberBuilder::new(subscriber_id.clone())
+        .set_interests([EventType::Milter(MilterEvent::ActionReplyCode)])
+        .with_lossy(false);
+    Collector::union_interests(subscriber.interests.clone());
+    let (_, mut events) = subscriber.register();
+    tokio::time::timeout(Duration::from_secs(5), async {
+        while !Collector::get_subscribers().contains(&subscriber_id) {
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+    })
+    .await
+    .expect("Milter trace subscriber was not registered");
+
+    // Test reply code: the SMTP response and its trace retain the Milter's code/text.
     session
         .send_message(
             "[email protected]",
             &["[email protected]"],
             "test:no_dkim",
-            "321",
+            "321 test",
         )
         .await;
     test.assert_no_events();
 
+    let event = tokio::time::timeout(Duration::from_secs(5), async {
+        loop {
+            for event in events.recv().await.expect("Milter trace subscriber closed") {
+                if event.span_id() == Some(session.data.session_id) {
+                    return event;
+                }
+            }
+        }
+    })
+    .await
+    .expect("Milter reply-code event was not emitted");
+    Collector::remove_subscriber(subscriber_id);
+    assert_eq!(
+        event.inner.typ,
+        EventType::Milter(MilterEvent::ActionReplyCode)
+    );
+    assert_eq!(event.value_as_uint(Key::Code), Some(321));
+    assert_eq!(event.value_as_str(Key::Details), Some("test"));
+
     // Test accept with header addition
     session
         .send_message(