fix: per-email error handling with connection rebuild, remove @retry on fetch

src/email_client.py

@@ -105,7 +105,6 @@ def _login_and_prepare(account: EmailAccount, timeout: int = 30):
     return conn
 
 
-@retry()
 def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
     conn = _login_and_prepare(account)
 
@@ -116,7 +115,6 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
 
     for uid in uids:
         try:
-            # 先查大小，大邮件用 PEEK 避免长时间阻塞导致连接断开被标已读
             _, size_data = conn.uid("FETCH", uid, "(RFC822.SIZE)")
             size = 0
             if size_data[0]:
@@ -125,9 +123,8 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
                     size = int(m.group(1))
             large = size > 200_000
             if large:
-                logger.info("UID %s 大邮件 (%d bytes)，用 PEEK 截断处理", uid, size)
+                logger.info("UID %s 大邮件 (%d bytes)，用 PEEK 拉取", uid, size)
 
-            # 大邮件用 PEEK 拉取，不触发服务器标记已读；小邮件正常拉
             fetch_cmd = "BODY.PEEK[]" if large else "RFC822"
             _, msg_data = conn.uid("FETCH", uid, fetch_cmd)
             if msg_data[0] is None:
@@ -148,10 +145,22 @@ def fetch_unseen_emails(account: EmailAccount) -> list[Email]:
             emails.append(Email(uid=uid, subject=subject, sender=sender, recipient=recipient,
                                 body=body, date=date_str, reply_to=reply_to, account_email=account.username))
         except Exception as e:
-            logger.error("UID %s FETCH 失败，跳过: %s", uid, e)
+            logger.error("UID %s FETCH 失败，跳过并重建连接: %s", uid, e)
+            try:
+                conn.logout()
+            except Exception:
+                pass
+            try:
+                conn = _login_and_prepare(account)
+            except Exception as e2:
+                logger.error("重建连接失败: %s", e2)
+                break
             continue
 
+    try:
         conn.logout()
+    except Exception:
+        pass
     logger.info("共获取 %d 封新邮件", len(emails))
     return emails