diff --git a/app/services/mail_store.py b/app/services/mail_store.py
index 98715ca..dda5c5f 100644
--- a/app/services/mail_store.py
+++ b/app/services/mail_store.py
@@ -43,8 +43,8 @@ class MailStore:
         logging.info(f"开始保存邮件: 发件人={sender}, 收件人={recipients}")
         logging.debug(f"原始邮件数据: {raw_data}")
         if recipients is None:
-            logging.warning("收件人列表为None，将使用空列表")
-            recipients_list = []
+            logging.error("收件人列表为None，无法保存邮件")
+            return False, "收件人列表为None"
         elif isinstance(recipients, list):
             recipients_list = recipients  # 如果是列表，直接使用
         else:
diff --git a/app/services/smtp_server.py b/app/services/smtp_server.py
index 332a1f3..038ba67 100644
--- a/app/services/smtp_server.py
+++ b/app/services/smtp_server.py
@@ -44,8 +44,11 @@ class EmailHandler(Message):
             
             # 检查收件人列表是否有效
             if not envelope.rcpt_tos:
-                logging.warning("收到邮件但没有有效收件人，将拒绝")
-                return '550 无效的收件人'
+                logging.error("收件人列表无效，无法保存邮件")
+                return '550 收件人列表无效'
+            elif not isinstance(envelope.rcpt_tos, (list, str)):
+                logging.error("收件人列表格式不正确，无法保存邮件")
+                return '550 收件人列表格式不正确'
             
             # 保存原始邮件数据
             raw_data = envelope.content.decode('utf-8', errors='replace')