diff --git a/codex-rs/agent-message-board-client/src/client.rs b/codex-rs/agent-message-board-client/src/client.rs
index d09804dc8b..178848b71d 100644
--- a/codex-rs/agent-message-board-client/src/client.rs
+++ b/codex-rs/agent-message-board-client/src/client.rs
@@ -363,8 +363,8 @@ impl AgentMessageBoard for RemoteAgentMessageBoard {
     );
 }
 
-/// One active turn's live receiver. The host must also check the turn atomically
-/// when injecting a returned notification, since the turn can end after `next`.
+/// One active turn's live receiver. Frames are checked against this receiver's
+/// identity before accepted notices enter the host's ordinary message delivery.
 pub struct BoardNotifications {
     caller: ThreadId,
     turn_id: String,
diff --git a/codex-rs/agent-message-board-client/src/notifications.rs b/codex-rs/agent-message-board-client/src/notifications.rs
index e6e534559a..1a5f96e3c1 100644
--- a/codex-rs/agent-message-board-client/src/notifications.rs
+++ b/codex-rs/agent-message-board-client/src/notifications.rs
@@ -112,7 +112,7 @@ impl TurnLifecycleContributor for Notifications {
 }
 
 /// Installs live notification delivery. The host resolves the existing remote
-/// client and a delivery host bound to this exact turn; idle agents are never woken.
+/// client and delivery host. Accepted notices use the host's ordinary message policy.
 /// The turn store owns the receiver and cancels it when the turn ends.
 pub fn install_notifications<C: Sync>(
     registry: &mut ExtensionRegistryBuilder<C>,
diff --git a/codex-rs/core/src/agent/control/residency.rs b/codex-rs/core/src/agent/control/residency.rs
index d0601c8900..3ea01481ab 100644
--- a/codex-rs/core/src/agent/control/residency.rs
+++ b/codex-rs/core/src/agent/control/residency.rs
@@ -171,15 +171,15 @@ impl LocalAgentRuntime {
     /// Pins and touches the registered runtime without waiting for unrelated eviction.
     pub(crate) async fn pin_v2_residency(
         &self,
-        state: &ThreadManagerState,
-        thread: &Arc<CodexThread>,
+        thread: &CodexThread,
     ) -> CodexResult<Option<tokio::sync::OwnedRwLockReadGuard<()>>> {
         if !is_resident_candidate(thread) {
             return Ok(None);
         }
         let guard = Arc::clone(&thread.residency_gate).read_owned().await;
         let thread_id = thread.session.thread_id;
-        if !Arc::ptr_eq(thread, &state.get_thread(thread_id).await?) {
+        let registered = self.upgrade()?.get_thread(thread_id).await?;
+        if !std::ptr::eq(thread, registered.as_ref()) {
             return Err(CodexErr::ThreadNotFound(thread_id));
         }
         self.residency.touch(thread_id);
diff --git a/codex-rs/core/src/agent/control/residency_tests.rs b/codex-rs/core/src/agent/control/residency_tests.rs
index 5bf450e456..e098af6440 100644
--- a/codex-rs/core/src/agent/control/residency_tests.rs
+++ b/codex-rs/core/src/agent/control/residency_tests.rs
@@ -7,11 +7,15 @@ use crate::config::test_config;
 use crate::thread_manager::ThreadManagerState;
 use codex_features::Feature;
 use codex_login::CodexAuth;
+use codex_protocol::AgentPath;
 use codex_protocol::ThreadId;
 use codex_protocol::error::CodexErrorDetails;
 use codex_protocol::protocol::EventMsg;
+use codex_protocol::protocol::InterAgentCommunication;
+use codex_protocol::protocol::Op;
 use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::SubAgentSource;
+use codex_protocol::protocol::ThreadSettingsOverrides;
 use codex_protocol::protocol::ThreadSource;
 use codex_protocol::protocol::TurnAbortReason;
 use codex_protocol::protocol::TurnAbortedEvent;
@@ -58,6 +62,29 @@ async fn residency_slot_reservation_unloads_oldest_idle_v2_agent() {
     first_slot.commit(first.thread_id);
     mark_thread_completed(first.thread.as_ref()).await;
 
+    // Public message submission must honor the same eviction gate as MAv2 sends.
+    let eviction_gate = Arc::clone(&first.thread.residency_gate).write_owned().await;
+    let communication = InterAgentCommunication::new(
+        AgentPath::root(),
+        AgentPath::try_from("/root/worker_1").unwrap(),
+        Vec::new(),
+        "queued notice".into(),
+        /*trigger_turn*/ false,
+    );
+    let delivery = first.thread.submit(Op::InterAgentCommunication {
+        communication: communication.clone(),
+        start_options: Default::default(),
+    });
+    tokio::pin!(delivery);
+    assert!(futures::poll!(delivery.as_mut()).is_pending());
+    drop(eviction_gate);
+    delivery.await.expect("submit after eviction gate releases");
+    first
+        .thread
+        .update_thread_settings(ThreadSettingsOverrides::default())
+        .await
+        .expect("dispatch queued notice before eviction");
+
     let second_slot = control
         .reserve_v2_residency_slot(
             &state,
@@ -74,6 +101,14 @@ async fn residency_slot_reservation_unloads_oldest_idle_v2_agent() {
         },
         Ok(_) => panic!("expected evicted thread to be missing"),
     }
+    let retained = first
+        .thread
+        .session
+        .services
+        .local_agent_runtime
+        .mailboxes
+        .take(first.thread_id);
+    assert_eq!(retained, vec![communication.into()]);
     let second = spawn_v2_subagent(&control, &state, config, root.thread_id, "worker-2").await;
     second_slot.commit(second.thread_id);
 
diff --git a/codex-rs/core/src/agent/control/spawn.rs b/codex-rs/core/src/agent/control/spawn.rs
index 9210827567..a4ac17f71a 100644
--- a/codex-rs/core/src/agent/control/spawn.rs
+++ b/codex-rs/core/src/agent/control/spawn.rs
@@ -264,7 +264,7 @@ impl LocalAgentControl {
         if owner_thread_id.is_none()
             && let Ok(thread) = state.get_thread(thread_id).await
         {
-            return self.runtime.pin_v2_residency(&state, &thread).await;
+            return self.runtime.pin_v2_residency(&thread).await;
         }
         if self
             .runtime
@@ -328,7 +328,7 @@ impl LocalAgentControl {
             }
             if let Ok(thread) = state.get_thread(thread_id).await {
                 self.validate_loaded_v2_child(&thread, parent_thread_id)?;
-                return self.runtime.pin_v2_residency(&state, &thread).await;
+                return self.runtime.pin_v2_residency(&thread).await;
             }
         }
         let parent = if let Some(parent) = parent {
@@ -589,9 +589,7 @@ impl LocalAgentControl {
                 // Finish registration even if the sender is cancelled while acquiring its pin.
                 tokio::spawn(async move {
                     let _membership = membership;
-                    let residency_pin = runtime
-                        .pin_v2_residency(&state, &reloaded_thread.thread)
-                        .await?;
+                    let residency_pin = runtime.pin_v2_residency(&reloaded_thread.thread).await?;
                     runtime.registry.clear_evicted_environments(thread_id);
                     residency_slot.commit(reloaded_thread.thread_id);
                     // Register before listeners can forward events from the resumed thread.
@@ -616,7 +614,7 @@ impl LocalAgentControl {
                     }
                     self.runtime.registry.clear_evicted_environments(thread_id);
                     drop(residency_slot);
-                    return self.runtime.pin_v2_residency(&state, &thread).await;
+                    return self.runtime.pin_v2_residency(&thread).await;
                 }
                 Err(err)
             }
diff --git a/codex-rs/core/src/agent_message_board.rs b/codex-rs/core/src/agent_message_board.rs
index 12cd8ec42b..c9dc09505f 100644
--- a/codex-rs/core/src/agent_message_board.rs
+++ b/codex-rs/core/src/agent_message_board.rs
@@ -2,7 +2,7 @@
 //!
 //! The extension owns backend construction, storage and tool registration. This adapter
 //! selects configuration and supplies host capabilities. It never starts or restores
-//! recipients and never queues a notification for an idle agent.
+//! recipients during lookup. Notifications use ordinary agent-message scheduling.
 
 use crate::CodexThread;
 use crate::ThreadManager;
@@ -28,6 +28,7 @@ use codex_protocol::error::CodexErr;
 use codex_protocol::error::CodexErrorDetails;
 use codex_protocol::error::Result;
 use codex_protocol::protocol::InterAgentCommunication;
+use codex_protocol::protocol::Op;
 use futures::future::BoxFuture;
 use std::sync::Arc;
 use std::sync::Weak;
@@ -44,7 +45,7 @@ pub fn install_agent_message_board(
         Some((
             board,
             Arc::new(LocalBoardHost {
-                expected_turn_id: Some(input.turn_id.into()),
+                remote_notifications: true,
                 ..host.as_ref().clone()
             }),
         ))
@@ -91,7 +92,7 @@ pub fn install_agent_message_board(
                     manager: manager.clone(),
                     tree,
                     caller,
-                    expected_turn_id: None,
+                    remote_notifications: false,
                     connection,
                 },
             ))
@@ -104,7 +105,7 @@ struct LocalBoardHost {
     manager: Weak<ThreadManager>,
     tree: SessionId,
     caller: ThreadId,
-    expected_turn_id: Option<String>,
+    remote_notifications: bool,
     connection: Option<Arc<LocalBoardConnection>>,
 }
 
@@ -237,7 +238,7 @@ impl MessageBoardHost for LocalBoardHost {
             );
             // Remote metadata is untrusted. Skip an oversized notice without closing
             // the receiver; the post remains available through the board tools.
-            if self.expected_turn_id.is_some()
+            if self.remote_notifications
                 && communication.content.len()
                     + communication.author.as_str().len()
                     + communication.recipient.as_str().len()
@@ -247,22 +248,13 @@ impl MessageBoardHost for LocalBoardHost {
                     "remote board notice exceeds the context budget".into(),
                 ));
             }
-            Ok(
-                if recipient
-                    .session
-                    .input_queue
-                    .deliver_mailbox_communication_to_current_turn(
-                        &recipient.session.active_turn,
-                        communication,
-                        self.expected_turn_id.as_deref(),
-                    )
-                    .await
-                {
-                    NotificationDelivery::Accepted
-                } else {
-                    NotificationDelivery::SkippedInactive
-                },
-            )
+            recipient
+                .submit(Op::InterAgentCommunication {
+                    communication,
+                    start_options: Default::default(),
+                })
+                .await?;
+            Ok(NotificationDelivery::Accepted)
         })
     }
 }
diff --git a/codex-rs/core/src/codex_thread.rs b/codex-rs/core/src/codex_thread.rs
index 60de98ddbc..ff23071182 100644
--- a/codex-rs/core/src/codex_thread.rs
+++ b/codex-rs/core/src/codex_thread.rs
@@ -242,7 +242,7 @@ impl CodexThread {
     }
 
     pub async fn submit(&self, op: Op) -> CodexResult<String> {
-        self.io.submit(op).await
+        self.submit_with_trace(op, /*trace*/ None).await
     }
 
     /// Returns the session telemetry handle for thread-scoped production instrumentation.
@@ -453,10 +453,24 @@ impl CodexThread {
         op: Op,
         trace: Option<W3cTraceContext>,
     ) -> CodexResult<String> {
+        // Use the same admission guard as MAv2 sends, retaining it through dispatch.
+        let residency_guard = if matches!(op, Op::InterAgentCommunication { .. }) {
+            self.session
+                .services
+                .local_agent_runtime
+                .pin_v2_residency(self)
+                .await?
+        } else {
+            None
+        };
         self.io
             .submit_with_trace(
-                op, trace, /*parent_turn_id*/ None, /*root_turn_id*/ None,
-                /*residency_guard*/ None, /*message_delivery*/ None,
+                op,
+                trace,
+                /*parent_turn_id*/ None,
+                /*root_turn_id*/ None,
+                residency_guard,
+                /*message_delivery*/ None,
             )
             .await
     }
diff --git a/codex-rs/core/src/session/input_queue.rs b/codex-rs/core/src/session/input_queue.rs
index de016d7ac9..b1100b12e8 100644
--- a/codex-rs/core/src/session/input_queue.rs
+++ b/codex-rs/core/src/session/input_queue.rs
@@ -7,7 +7,6 @@ use codex_diagnostics::GaugeGuard;
 use codex_history::ResponseItemEnvelope;
 use codex_protocol::ThreadId;
 use codex_protocol::models::ResponseItem;
-use codex_protocol::protocol::InterAgentCommunication;
 use codex_protocol::turn_input::TurnStartOptions;
 use codex_protocol::user_input::UserInput;
 use serde::Deserialize;
@@ -202,38 +201,6 @@ impl InputQueue {
         (activity_rx, pending_activity)
     }
 
-    #[expect(
-        clippy::await_holding_invalid_type,
-        reason = "active turn checks and turn state updates must remain atomic"
-    )]
-    pub(crate) async fn deliver_mailbox_communication_to_current_turn(
-        &self,
-        active_turn: &Mutex<Option<ActiveTurn>>,
-        communication: InterAgentCommunication,
-        expected_turn_id: Option<&str>,
-    ) -> bool {
-        let active = active_turn.lock().await;
-        let Some(active_turn) = active.as_ref().filter(|turn| {
-            turn.task.as_ref().is_some_and(|task| {
-                expected_turn_id.is_none_or(|id| {
-                    task.turn_context.sub_id == id && !task.cancellation_token.is_cancelled()
-                })
-            })
-        }) else {
-            return false;
-        };
-        let mut turn_state = active_turn.turn_state.lock().await;
-        if !turn_state.accepts_mailbox_delivery_for_current_turn() {
-            return false;
-        }
-        turn_state
-            .pending_input
-            .items
-            .push(TurnInput::InterAgentCommunication(communication.into()));
-        self.activity_tx.send_replace(InputQueueActivity::Mailbox);
-        true
-    }
-
     pub(crate) async fn enqueue_mailbox_communication(
         &self,
         communication: crate::PendingAgentMessage,
@@ -556,6 +523,7 @@ mod tests {
     use super::*;
     use codex_history::CodexHarnessMetadata;
     use codex_protocol::AgentPath;
+    use codex_protocol::protocol::InterAgentCommunication;
     use codex_protocol::user_input::UserInput;
     use pretty_assertions::assert_eq;
 
diff --git a/codex-rs/core/src/thread_manager.rs b/codex-rs/core/src/thread_manager.rs
index f07c7d18a0..5a5e48422c 100644
--- a/codex-rs/core/src/thread_manager.rs
+++ b/codex-rs/core/src/thread_manager.rs
@@ -1886,7 +1886,7 @@ impl ThreadManagerState {
                 .session
                 .services
                 .local_agent_runtime
-                .pin_v2_residency(self, &thread)
+                .pin_v2_residency(&thread)
                 .await?
         } else {
             None
diff --git a/codex-rs/core/tests/suite/scenarios_agent_message_board.rs b/codex-rs/core/tests/suite/scenarios_agent_message_board.rs
index dd1fbe82f5..88fa3f45d2 100644
--- a/codex-rs/core/tests/suite/scenarios_agent_message_board.rs
+++ b/codex-rs/core/tests/suite/scenarios_agent_message_board.rs
@@ -1,4 +1,4 @@
-//! Exercises board tools through the runtime, including resume and active-only notices.
+//! Exercises board tools through the runtime, including resume and native mailbox notifications.
 
 use anyhow::Context;
 use codex_core::TurnInputRequest;
@@ -7,6 +7,7 @@ use codex_message_board::PostMetadata;
 use codex_protocol::items::TurnItem;
 use codex_protocol::protocol::EventMsg;
 use codex_protocol::protocol::MultiAgentVersion;
+use codex_protocol::protocol::ThreadSettingsOverrides;
 use codex_protocol::user_input::UserInput;
 use core_test_support::context_snapshot;
 use core_test_support::context_snapshot::ContextSnapshotOptions;
@@ -250,7 +251,7 @@ async fn board_post_and_reads_reach_model_context_without_self_notices(
 #[test_case::test_case(false; "disk")]
 #[test_case::test_case(true; "in_memory")]
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn board_is_shared_with_children_and_skips_idle_notices(
+async fn board_is_shared_with_children_and_queues_idle_notices(
     in_memory: bool,
 ) -> anyhow::Result<()> {
     let server = responses::start_mock_server().await;
@@ -341,11 +342,7 @@ async fn board_is_shared_with_children_and_skips_idle_notices(
     )
     .await;
     root.submit_turn("Read the worker's decision.").await?;
-    assert!(
-        read.requests()
-            .iter()
-            .all(|request| !request.body_contains_text("Message Type: CHANNEL_POST"))
-    );
+    assert!(read.requests()[1].body_contains_text("Message Type: CHANNEL_POST"));
     let output = read.requests()[1]
         .function_call_output_text("root-read")
         .expect("read result");
@@ -454,7 +451,8 @@ async fn board_notifications_do_not_reopen_a_final_answer(
             gate: Some(child_gate),
             body: done(),
         }],
-        response(done()),
+        // Native mail is drained after the new task's first model step.
+        response(tool("next-step", "get_channels", json!({}))),
         response(done()),
     ])
     .await;
@@ -550,18 +548,22 @@ async fn board_notifications_do_not_reopen_a_final_answer(
     let next_turn = requests.last().context("next root request")?["client_metadata"]["turn_id"]
         .as_str()
         .context("next root turn ID")?;
-    for (turn, notified) in [(target_turn.as_str(), false), (next_turn, !after_final)] {
+    for (turn, expected_requests, notified) in
+        [(target_turn.as_str(), 1, false), (next_turn, 2, true)]
+    {
         let requests = requests
             .iter()
             .filter(|request| request["client_metadata"]["turn_id"] == turn)
             .collect::<Vec<_>>();
         assert_eq!(
             requests.len(),
-            1,
-            "recipient must not sample again after its final"
+            expected_requests,
+            "unexpected sampling count for root turn {turn}"
         );
         assert_eq!(
-            requests[0]["input"].to_string().contains(&notification),
+            requests.last().context("root request")?["input"]
+                .to_string()
+                .contains(&notification),
             notified
         );
     }
@@ -955,6 +957,8 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
     let server = responses::start_mock_server().await;
     let response = |body| vec![StreamingSseChunk { gate: None, body }];
     let (release, gate) = oneshot::channel();
+    let mut started = ev_message_item_added("watching", "");
+    started["item"]["phase"] = json!("commentary");
     let mut working = ev_assistant_message("watching", "Watching the policy board.");
     working["item"]["phase"] = json!("commentary");
     let (streaming, _) = start_streaming_sse_server(vec![
@@ -984,11 +988,15 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
         vec![
             StreamingSseChunk {
                 gate: None,
-                body: sse(vec![ev_response_created("watching"), working]),
+                body: sse(vec![ev_response_created("watching"), started]),
             },
             StreamingSseChunk {
                 gate: Some(gate),
-                body: tool("checkpoint", "get_channels", json!({})),
+                body: sse(vec![
+                    working,
+                    ev_function_call_with_namespace("checkpoint", "collaboration", "get_channels", "{}"),
+                    ev_completed("checkpoint"),
+                ]),
             },
         ],
         // Separate responses order the writes before snapshotting last_message_id.
@@ -1015,6 +1023,8 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
             }),
         )),
         response(done()),
+        // Queued board notices preempt the commentary before its planned checkpoint.
+        response(tool("checkpoint", "get_channels", json!({}))),
         response(done()),
     ])
     .await;
@@ -1132,8 +1142,13 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
             text_elements: vec![],
         }]))
         .await?;
+    let guardian_turn = wait_for_event_match(guardian, |event| match event {
+        EventMsg::TurnStarted(event) => Some(event.turn_id.clone()),
+        _ => None,
+    })
+    .await;
     wait_for_event(guardian, |event| {
-        matches!(event, EventMsg::ItemCompleted(event)
+        matches!(event, EventMsg::ItemStarted(event)
         if matches!(&event.item, TurnItem::AgentMessage(message) if message.id == "watching"))
     })
     .await;
@@ -1144,6 +1159,16 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
         }]))
         .await?;
     wait_for_event(writer, |event| matches!(event, EventMsg::TurnComplete(_))).await;
+    // Acknowledgement is ordered after both notices in the recipient's submission queue.
+    guardian
+        .update_thread_settings(ThreadSettingsOverrides::default())
+        .await?;
+    assert_eq!(
+        guardian
+            .wait_for_input_activity(&guardian_turn, std::time::Duration::from_secs(/*secs*/ 10))
+            .await,
+        codex_core::InputWaitOutcome::MailboxActivity,
+    );
     release
         .send(())
         .expect("release Guardian after notification delivery");
@@ -1154,6 +1179,20 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
             .iter()
             .any(|body| String::from_utf8_lossy(body).contains("Message Type: CHANNEL_POST"))
     );
+    let resumed: Value = serde_json::from_slice(&requests[16])?;
+    assert!(
+        resumed["input"]
+            .to_string()
+            .contains("Message Type: CHANNEL_POST")
+    );
+    assert!(
+        !resumed["input"]
+            .as_array()
+            .context("resumed input")?
+            .iter()
+            .any(|item| item["call_id"] == "checkpoint"),
+        "queued board mail must be read before the planned checkpoint runs",
+    );
     let last: Value = serde_json::from_slice(requests.last().unwrap())?;
     let checkpoint = last["input"]
         .as_array()
@@ -1169,7 +1208,7 @@ async fn codex_instances_share_board_with_fixed_access() -> anyhow::Result<()> {
         .iter()
         .map(|body| serde_json::from_slice::<Value>(body))
         .collect::<serde_json::Result<Vec<_>>>()?;
-    assert_eq!(bodies.len(), 17);
+    assert_eq!(bodies.len(), 18);
     for body in &mut bodies {
         for item in body["input"].as_array_mut().context("request input")? {
             if let Some(Value::String(output)) = item.get_mut("output") {
diff --git a/codex-rs/core/tests/suite/scenarios_agent_message_board_http.rs b/codex-rs/core/tests/suite/scenarios_agent_message_board_http.rs
index 06667f15e9..0d54d86443 100644
--- a/codex-rs/core/tests/suite/scenarios_agent_message_board_http.rs
+++ b/codex-rs/core/tests/suite/scenarios_agent_message_board_http.rs
@@ -200,15 +200,14 @@ async fn http_board_is_shared_with_children(mode: BoardMode) -> anyhow::Result<(
             .map_or(output.as_str(), |(_, json)| json);
         serde_json::from_str(json).with_context(|| format!("board result: {output}"))
     };
-    let posted = responses::mount_sse_sequence(
-        &server,
-        board_turn(
-            "worker-post",
-            "post",
-            json!({"new_channel_name":"design","text":"Worker's durable decision."}),
-        ),
-    )
-    .await;
+    let mut post_arguments =
+        json!({"new_channel_name":"design","text":"Worker's durable decision."});
+    if mode == BoardMode::Feature {
+        post_arguments["agents_to_notify"] = json!(["/root"]);
+    }
+    let posted =
+        responses::mount_sse_sequence(&server, board_turn("worker-post", "post", post_arguments))
+            .await;
     child
         .start_or_steer_turn(TurnInputRequest::user_input(vec![UserInput::Text {
             text: "Find the board tools and post your decision.".into(),
@@ -261,6 +260,9 @@ async fn http_board_is_shared_with_children(mode: BoardMode) -> anyhow::Result<(
     if let Some(writer) = writer {
         writer.rollback().await?;
     }
+    if mode == BoardMode::Feature {
+        assert!(read.requests()[1].body_contains_text("Message Type: CHANNEL_POST"));
+    }
     let result = board_result(
         read.requests().last().context("parent follow-up")?,
         "root-read",
diff --git a/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__board_connections.snap b/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__board_connections.snap
index f4be7df78a..145c06b61d 100644
--- a/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__board_connections.snap
+++ b/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__board_connections.snap
@@ -116,7 +116,8 @@ Scenario: Independent Codex runtimes share a local board: a writer publishes, an
 21:function_call_output:{"channel_name":"policy","enabled":true,"last_message_id":"<UUID 1>","target_agent":"/root/00000000000040008000000000000001","thread_id":null}
 22:message/assistant:
     Watching the policy board.
-23:function_call/collaboration.get_channels:{}
-24:function_call_output:{"board_permissions":{"create_channel":false,"edit_metadata":false,"manage_permissions":false},"has_more...ata":false,"post":false,"read":true,"reply":false}}]} [hash=7cc8dc25fc1c52b2]
-25:agent_message
-26:agent_message
+23:agent_message
+24:agent_message
+-- request 18 (request) --
+25:function_call/collaboration.get_channels:{}
+26:function_call_output:{"board_permissions":{"create_channel":false,"edit_metadata":false,"manage_permissions":false},"has_more...ata":false,"post":false,"read":true,"reply":false}}]} [hash=7cc8dc25fc1c52b2]
diff --git a/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__http__agent_message_board_mcp_feature_context.snap b/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__http__agent_message_board_mcp_feature_context.snap
index 98ac248bb0..932c573fd5 100644
--- a/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__http__agent_message_board_mcp_feature_context.snap
+++ b/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__http__agent_message_board_mcp_feature_context.snap
@@ -45,7 +45,7 @@ Scenario: The config flag starts an in-memory MCP board shared by a parent and c
 08:tool_search_call
 09:tool_search_output
 -- request 3 (request) --
-10:function_call/mcp__codex_message_board.post:{"new_channel_name":"design","text":"Worker's durable decision."}
+10:function_call/mcp__codex_message_board.post:{"agents_to_notify":["/root"],"new_channel_name":"design","text":"Worker's durable decision."}
 11:function_call_output:Wall time: <DURATION> seconds
     Output:
     {"author":"/root/worker","channel_name":"design","created_at":"<TIMESTAMP>","message_id":"<UUID 1>","thread_id":"<UUID 1>"}
@@ -95,8 +95,9 @@ Scenario: The config flag starts an in-memory MCP board shared by a parent and c
 11:tool_search_output
 12:agent_message
 13:agent_message
+14:agent_message
 -- request 6 (request) --
-14:function_call/mcp__codex_message_board.search_posts:{"channel_name":"design"}
-15:function_call_output:Wall time: <DURATION> seconds
+15:function_call/mcp__codex_message_board.search_posts:{"channel_name":"design"}
+16:function_call_output:Wall time: <DURATION> seconds
     Output:
     {"has_more":false,"n_returned":1,"next_cursor":null,"results":[{"author":"/root/worker","channel_name":"...ecision.","thread_id":"<UUID 1>","truncated":false}]} [hash=0322071c1fb9baa5]
diff --git a/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__remote__remote_board_permissions_direct.snap b/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__remote__remote_board_permissions_direct.snap
index e07c147301..041aeed072 100644
--- a/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__remote__remote_board_permissions_direct.snap
+++ b/codex-rs/core/tests/suite/snapshots/all__suite__scenarios__agent_message_board__remote__remote_board_permissions_direct.snap
@@ -6,7 +6,7 @@ Scenario: Permission discovery preserves legacy output, exposes reply-only acces
 
 ## Window 1
 -- request 1 (request) --
-00:additional_tools/developer (3; hash=e49a28343a9fe4ed):
+00:additional_tools/developer (3; hash=788c4a5014dcfe4f):
         - namespace/functions; hash=c8b8fa91706a7620
           - function/exec_command
           - function/write_stdin
@@ -17,7 +17,7 @@ Scenario: Permission discovery preserves legacy output, exposes reply-only acces
         - namespace/clock: Tools for reading and waiting on time.; hash=a80435c7a3a3943f
           - function/curr_time
           - function/sleep
-        - namespace/collaboration: Tools for spawning and managing sub-agents.; hash=ba5664aaab81db64
+        - namespace/collaboration: Tools for spawning and managing sub-agents.; hash=5c5c29d91fa33d4a
           - function/create_channel
           - function/followup_task
           - function/get_channels
diff --git a/codex-rs/message-board/src/host.rs b/codex-rs/message-board/src/host.rs
index c915a41b8d..494d862b09 100644
--- a/codex-rs/message-board/src/host.rs
+++ b/codex-rs/message-board/src/host.rs
@@ -18,10 +18,9 @@ pub enum NotificationDelivery {
 ///
 /// The host remains authoritative for membership even when runtimes are unloaded.
 /// Clock reads use the posting agent's configured source, including simulated
-/// time. Notifications are accepted only while a running turn still accepts
-/// mailbox delivery; otherwise they are skipped without being queued.
-/// Accepted notifications must not start a new turn or reopen a finalized answer,
-/// but may remain in conversation history for a later turn.
+/// time. Notifications follow the host's ordinary queue-only agent-message
+/// scheduling and wake policy, and may be buffered for an idle recipient.
+/// Acceptance does not guarantee that the model has consumed the notification.
 /// Backends may implement these capabilities with local handles or remote RPCs.
 pub trait MessageBoardHost: Send + Sync {
     fn agent_path(&self, caller: ThreadId) -> BoxFuture<'_, Result<AgentPath>>;
diff --git a/codex-rs/message-board/src/tools/spec.rs b/codex-rs/message-board/src/tools/spec.rs
index 88ebb1a9ac..e9691e5ffd 100644
--- a/codex-rs/message-board/src/tools/spec.rs
+++ b/codex-rs/message-board/src/tools/spec.rs
@@ -66,7 +66,7 @@ pub(super) fn tool(
             &["message_id"],
         ),
         MessageBoardTool::Subscribe => (
-            "Subscribe yourself or another agent to a channel for new top-level posts, or to a thread for replies. Provide exactly one of channel_name or thread_id. Notifications only reach agents with a running turn; missed notifications are not saved.",
+            "Subscribe yourself or another agent to a channel for new top-level posts, or to a thread for replies. Provide exactly one of channel_name or thread_id. Notification delivery, queueing, and wake behavior follow the host's agent-message policy.",
             &["channel_name", "thread_id", "target_agent"],
             &[],
         ),
@@ -76,7 +76,7 @@ pub(super) fn tool(
             &[],
         ),
         MessageBoardTool::Post => (
-            "Start a thread in an existing or new channel, or reply using the first post's message ID as thread_id. Exactly one destination is required. Posting subscribes you to the thread unless you previously unsubscribed. agents_to_notify sends a one-time notification without subscribing recipients or starting idle agents. Returns metadata, not the post text.",
+            "Start a thread in an existing or new channel, or reply using the first post's message ID as thread_id. Exactly one destination is required. Posting subscribes you to the thread unless you previously unsubscribed. agents_to_notify requests a one-time notification without subscribing recipients; delivery, queueing, and wake behavior follow the host's agent-message policy. Returns metadata, not the post text.",
             &[
                 "text",
                 "channel_name",