diff --git a/app/services/mail_store.py b/app/services/mail_store.py
index 6d56637..0116ba5 100644
--- a/app/services/mail_store.py
+++ b/app/services/mail_store.py
@@ -84,7 +84,13 @@ class MailStore:
             try:
                 # 查找收件人对应的邮箱
                 mailbox_id = None
-                recipients_list = recipients if isinstance(recipients, list) else [recipients]
+                
+                # 处理recipients为None的情况
+                if recipients is None:
+                    logging.warning("收件人列表为None，将使用空列表")
+                    recipients_list = []
+                else:
+                    recipients_list = recipients if isinstance(recipients, list) else [recipients]
                 
                 # 确保收件人列表不为空
                 if not recipients_list:
diff --git a/app/services/smtp_server.py b/app/services/smtp_server.py
index f966452..3939fe0 100644
--- a/app/services/smtp_server.py
+++ b/app/services/smtp_server.py
@@ -39,36 +39,49 @@ class EmailHandler(Message):
     async def handle_DATA(self, server, session, envelope):
         """处理邮件数据"""
         try:
-            # 获取邮件数据
-            message_data = envelope.content.decode('utf-8', errors='replace')
+            logging.info(f"收到邮件: 发件人={envelope.mail_from}, 收件人={envelope.rcpt_tos}")
             
-            # 记录接收到的邮件
-            sender = envelope.mail_from
-            recipients = envelope.rcpt_tos
+            # 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.info(f"SMTP服务收到邮件: 发件人={sender}, 收件人={recipients}")
+            # 保存原始邮件数据
+            raw_data = envelope.content.decode('utf-8', errors='replace')
             
-            # 使用email.parser解析邮件
-            parser = email.parser.Parser(policy=default)
-            message = parser.parsestr(message_data)
+            # 解析邮件数据
+            message = email_parser.Parser(policy=default).parsestr(raw_data)
+            subject = message.get('Subject', '')
+            logging.info(f"邮件主题: {subject}")
             
-            # 保存邮件
-            success, result_message = await self.mail_store.save_email(message, sender, recipients, message_data)
+            # 记录邮件结构和内容
+            logging.debug(f"邮件结构: is_multipart={message.is_multipart()}")
+            if message.is_multipart():
+                logging.debug(f"多部分邮件: 部分数量={len(list(message.walk()))}")
+                for i, part in enumerate(message.walk()):
+                    content_type = part.get_content_type()
+                    logging.debug(f"部分 {i+1}: 内容类型={content_type}")
+            
+            # 使用邮件存储服务保存邮件
+            success, error_msg = await self.mail_store.save_email(
+                message, 
+                envelope.mail_from, 
+                envelope.rcpt_tos, 
+                raw_data=raw_data
+            )
             
             if success:
-                logging.info(f"邮件已成功保存: {result_message}")
-                return '250 Message accepted for delivery'
+                logging.info(f"邮件保存成功: 来自 {envelope.mail_from} 发送给 {envelope.rcpt_tos}")
+                return '250 消息接收完成'
             else:
-                logging.error(f"邮件保存失败: {result_message}")
-                # 注意：即使保存失败，我们仍然返回成功，避免发件方重试
-                # 这是因为问题通常在我们的系统中，重试不会解决问题
-                return '250 Message accepted for delivery (warning: internal processing error)'
-        
+                logging.error(f"邮件保存失败: {error_msg}")
+                # 即使保存失败，也返回成功状态码，避免邮件服务器重试
+                return '250 消息已收到'
+                
         except Exception as e:
             logging.error(f"处理邮件时出错: {str(e)}")
             traceback.print_exc()
-            # 返回临时错误，让发件方可以重试
-            return '451 Requested action aborted: local error in processing'
+            return '451 处理邮件时出现错误，请稍后重试'
 
 
 # 为Windows环境自定义SMTP控制器