diff --git a/src/daemon/dispatcher.py b/src/daemon/dispatcher.py
index 484be52..14787dc 100644
--- a/src/daemon/dispatcher.py
+++ b/src/daemon/dispatcher.py
@@ -229,8 +229,6 @@ class Dispatcher:
                                 logger.error("Mail %s: on_complete error: %s", _task_id, e)
                         else:
                             logger.info("Mail %s: on_complete outcome=%s, skip auto-done", _task_id, outcome)
-                            if _counter:
-                                _counter.release(aid)
                     on_complete = _mail_on_complete
                 else:
                     on_complete = (
@@ -472,6 +470,18 @@ class Dispatcher:
             try:
                 if self.counter:
                     await self.counter.acquire(agent_id)
+
+                # [v2.7.1] Mail: spawn 前系统标 working
+                is_mail_legacy = project_config.get("project_id") == "_mail" if project_config else False
+                if is_mail_legacy:
+                    db_path_legacy = Path(project_config["db_path"]) if project_config and "db_path" in project_config else None
+                    if not db_path_legacy or not self._mail_auto_working(task.id, db_path_legacy):
+                        if self.counter:
+                            self.counter.release(agent_id)
+                        return {"level": level.value, "agent_id": agent_id,
+                                "session_id": None, "status": "error",
+                                "reason": "mail_auto_working_failed"}
+
                 if hasattr(self.spawner, 'build_spawn_message') and project_config:
                     retry_ctx = self._build_retry_context(task)
                     message = self.spawner.build_spawn_message(
@@ -487,16 +497,38 @@ class Dispatcher:
                     )
                 else:
                     message = f"Task: {task.title}"
-                # Agent 完成后自动 release counter
-                on_complete = (
-                    lambda aid, _outcome: self.counter.release(aid)
-                ) if self.counter else None
+                # [v2.7.1] Mail: on_complete 增强
+                on_complete_legacy = None
+                if is_mail_legacy:
+                    _t_id = task.id
+                    _a_id = agent_id
+                    _m_db = db_path_legacy
+                    _m_mh = task.must_haves or ""
+                    _ct = self.counter
+                    _disp = self
+
+                    def _mail_oc_legacy(aid, outcome):
+                        if _ct:
+                            _ct.release(aid)
+                        if outcome in ("completed", "agent_failed"):
+                            try:
+                                _disp._mail_auto_complete(_t_id, aid, _m_db, _m_mh)
+                            except Exception as e:
+                                logger.error("Mail %s: legacy on_complete error: %s", _t_id, e)
+                        else:
+                            logger.info("Mail %s: legacy on_complete outcome=%s, skip auto-done", _t_id, outcome)
+                    on_complete_legacy = _mail_oc_legacy
+                else:
+                    on_complete_legacy = (
+                        lambda aid, _outcome: self.counter.release(aid)
+                    ) if self.counter else None
+
                 session_id = await self.spawner.spawn_full_agent(
                     agent_id=agent_id, message=message,
                     new_session=decision.get("new_session", False),
                     task_id=task.id,
-                    on_complete=on_complete,
-                    use_main_session=project_config.get("project_id") == "_mail" if project_config else False,
+                    on_complete=on_complete_legacy,
+                    use_main_session=is_mail_legacy,
                     task_db_path=Path(project_config["db_path"]) if project_config and "db_path" in project_config else None,
                 )
                 return {"level": level.value, "agent_id": agent_id,