diff --git a/codex-rs/core/src/session/mail_publication_tests.rs b/codex-rs/core/src/session/mail_publication_tests.rs
new file mode 100644
index 0000000000..3db44468c6
--- /dev/null
+++ b/codex-rs/core/src/session/mail_publication_tests.rs
@@ -0,0 +1,92 @@
+//! Mail delivery order and timestamp persistence in the recipient rollout.
+#![cfg(test)]
+
+use super::*;
+use pretty_assertions::assert_eq;
+
+#[tokio::test]
+async fn record_inter_agent_communication_sets_turn_id_in_rollout_and_resume() {
+    let (mut session, turn_context) = make_session_and_context().await;
+    let rollout_path = attach_thread_persistence(&mut session).await;
+    let communication = InterAgentCommunication::new(
+        AgentPath::root().join("worker").expect("worker path"),
+        AgentPath::root(),
+        Vec::new(),
+        "child done".to_string(),
+        /*trigger_turn*/ false,
+    );
+    let mut expected_item = communication.to_model_input_item();
+    let mut expected = serde_json::to_value(&expected_item).unwrap();
+    expected["internal_chat_message_metadata_passthrough"] = json!({
+        "content_item_metadata": [{"harness_injected": true, "source_tool_namespace": "collaboration"}],
+    });
+    expected_item = serde_json::from_value(expected).unwrap();
+    expected_item.set_turn_id_if_missing(&turn_context.sub_id);
+
+    session
+        .record_inter_agent_communication(&turn_context, turn_context.model_info(), communication)
+        .await;
+
+    let recorded_history = session.clone_history().await;
+    let recorded_items = raw_history_items(&recorded_history);
+    let create_time = recorded_items[0]
+        .executed_tool_call_metadata()
+        .and_then(|metadata| metadata.create_time.clone())
+        .expect("locally authored agent message should receive a creation timestamp");
+    assert!(create_time.as_f64().is_some_and(|seconds| seconds > 0.0));
+    expected_item.set_create_time_if_missing(create_time);
+
+    assert_eq!(
+        strip_response_item_ids(&recorded_items),
+        strip_response_item_ids(std::slice::from_ref(&expected_item))
+    );
+
+    session.flush_rollout().await.expect("rollout should flush");
+    let InitialHistory::Resumed(resumed) = RolloutRecorder::get_rollout_history(&rollout_path)
+        .await
+        .expect("read rollout history")
+    else {
+        panic!("expected resumed rollout history");
+    };
+    let persisted_items = resumed
+        .history
+        .iter()
+        .filter(|item| {
+            matches!(
+                item,
+                RolloutItem::ResponseItem(_)
+                    | RolloutItem::InterAgentCommunication(_)
+                    | RolloutItem::InterAgentCommunicationMetadata { .. }
+            )
+        })
+        .cloned()
+        .collect::<Vec<_>>();
+    let expected_persisted_items = vec![
+        RolloutItem::InterAgentCommunicationMetadata {
+            trigger_turn: false,
+        },
+        RolloutItem::ResponseItem(ResponseItemEnvelope {
+            item: expected_item.clone(),
+            metadata: Some(CodexHarnessMetadata {
+                user_input_order: Some(0),
+                history_sequence: Some(1),
+                sampled_through_sequence: Some(0),
+                ..Default::default()
+            }),
+        }),
+    ];
+    assert_eq!(
+        strip_response_item_ids_from_json(serde_json::to_value(persisted_items).unwrap()),
+        strip_response_item_ids_from_json(serde_json::to_value(expected_persisted_items).unwrap())
+    );
+
+    let (resumed_session, _resumed_turn_context) = make_session_and_context().await;
+    resumed_session
+        .record_initial_history(InitialHistory::Resumed(resumed))
+        .await;
+    assert_eq!(
+        strip_response_item_ids(&raw_history_items(&resumed_session.clone_history().await)),
+        strip_response_item_ids(std::slice::from_ref(&expected_item))
+    );
+    assert_eq!(resumed_session.reserve_user_input_order().await, 1);
+}
diff --git a/codex-rs/core/src/session/mod.rs b/codex-rs/core/src/session/mod.rs
index 1d438fce8e..7f38ba30cb 100644
--- a/codex-rs/core/src/session/mod.rs
+++ b/codex-rs/core/src/session/mod.rs
@@ -4736,6 +4736,8 @@ impl Session {
         for mut recording in pending {
             let _ = recording.changed().await;
         }
+        let mut delivery = communication.delivery.as_ref();
+        let mut result_write = None;
         {
             let mut state = self.state.lock().await;
             state.current_time_reminder.note_recorded_items(&items);
@@ -4744,7 +4746,9 @@ impl Session {
                 model_info.truncation_policy.into(),
             );
         }
-        let result_write = communication.consumed(self.thread_id);
+        if let Some(delivery) = delivery.take() {
+            result_write = delivery.consumed(self.thread_id);
+        }
         let saved = self
             .persist_rollout_items(&[
                 RolloutItem::InterAgentCommunicationMetadata {
@@ -4954,6 +4958,7 @@ impl Session {
             state
                 .history
                 .set_world_state_baseline(world_state_baseline.clone());
+            let resume_metadata = self.compaction_resume_metadata(&state);
             let compacted_item = CompactedItem {
                 message: metadata.message,
                 replacement_history: Some(replacement_history),
@@ -4966,7 +4971,7 @@ impl Session {
                 window_id: Some(metadata.window_ids.window_id),
                 compaction_response_id: metadata.compaction_response_id,
                 latest_token_usage_record: state.latest_token_usage_record.clone(),
-                resume_metadata: Some(self.compaction_resume_metadata(&state)),
+                resume_metadata: Some(resume_metadata),
             };
             (compacted_item, world_state_baseline, started_item)
         };
diff --git a/codex-rs/core/src/session/tests.rs b/codex-rs/core/src/session/tests.rs
index 8731bfe3ec..87a00abc5c 100644
--- a/codex-rs/core/src/session/tests.rs
+++ b/codex-rs/core/src/session/tests.rs
@@ -2617,92 +2617,8 @@ async fn inter_agent_communication_waits_for_confirmed_delivery_persistence() {
     assert_eq!(messages, vec![message]);
 }
 
-#[tokio::test]
-async fn record_inter_agent_communication_sets_turn_id_in_rollout_and_resume() {
-    let (mut session, turn_context) = make_session_and_context().await;
-    let rollout_path = attach_thread_persistence(&mut session).await;
-    let communication = InterAgentCommunication::new(
-        AgentPath::root().join("worker").expect("worker path"),
-        AgentPath::root(),
-        Vec::new(),
-        "child done".to_string(),
-        /*trigger_turn*/ false,
-    );
-    let mut expected_item = communication.to_model_input_item();
-    let mut expected = serde_json::to_value(&expected_item).unwrap();
-    expected["internal_chat_message_metadata_passthrough"] = json!({
-        "content_item_metadata": [{"harness_injected": true, "source_tool_namespace": "collaboration"}],
-    });
-    expected_item = serde_json::from_value(expected).unwrap();
-    expected_item.set_turn_id_if_missing(&turn_context.sub_id);
-
-    session
-        .record_inter_agent_communication(&turn_context, turn_context.model_info(), communication)
-        .await;
-
-    let recorded_history = session.clone_history().await;
-    let recorded_items = raw_history_items(&recorded_history);
-    let create_time = recorded_items[0]
-        .executed_tool_call_metadata()
-        .and_then(|metadata| metadata.create_time.clone())
-        .expect("locally authored agent message should receive a creation timestamp");
-    assert!(create_time.as_f64().is_some_and(|seconds| seconds > 0.0));
-    expected_item.set_create_time_if_missing(create_time);
-
-    assert_eq!(
-        strip_response_item_ids(&recorded_items),
-        strip_response_item_ids(std::slice::from_ref(&expected_item))
-    );
-
-    session.flush_rollout().await.expect("rollout should flush");
-    let InitialHistory::Resumed(resumed) = RolloutRecorder::get_rollout_history(&rollout_path)
-        .await
-        .expect("read rollout history")
-    else {
-        panic!("expected resumed rollout history");
-    };
-    let persisted_items = resumed
-        .history
-        .iter()
-        .filter(|item| {
-            matches!(
-                item,
-                RolloutItem::ResponseItem(_)
-                    | RolloutItem::InterAgentCommunication(_)
-                    | RolloutItem::InterAgentCommunicationMetadata { .. }
-            )
-        })
-        .cloned()
-        .collect::<Vec<_>>();
-    let expected_persisted_items = vec![
-        RolloutItem::InterAgentCommunicationMetadata {
-            trigger_turn: false,
-        },
-        RolloutItem::ResponseItem(ResponseItemEnvelope {
-            item: expected_item.clone(),
-            metadata: Some(CodexHarnessMetadata {
-                user_input_order: Some(0),
-                history_sequence: Some(1),
-                sampled_through_sequence: Some(0),
-                ..Default::default()
-            }),
-        }),
-    ];
-    assert_eq!(
-        strip_response_item_ids_from_json(serde_json::to_value(persisted_items).unwrap()),
-        strip_response_item_ids_from_json(serde_json::to_value(expected_persisted_items).unwrap())
-    );
-
-    let (resumed_session, _resumed_turn_context) = make_session_and_context().await;
-    resumed_session
-        .record_initial_history(InitialHistory::Resumed(resumed))
-        .await;
-    assert_eq!(
-        strip_response_item_ids(&raw_history_items(&resumed_session.clone_history().await)),
-        strip_response_item_ids(std::slice::from_ref(&expected_item))
-    );
-    assert_eq!(resumed_session.reserve_user_input_order().await, 1);
-}
+#[path = "mail_publication_tests.rs"]
+mod mail_publication_tests;
 
 #[tokio::test]
 async fn record_inter_agent_communication_preserves_item_id_in_rollout_and_resume() {