退信

• 退信提示："authentication required"
• 退信提示："the server need auth"
• 退信提示："requires authentication"
• 退信提示："AUTH FAILED"
• 退信提示："553 authentication is required"
• 退信提示："User suspended"
• 退信提示："not allowed to send email to this user"
• 退信提示："deliver to local org only"
• 退信提示："SDN51"
• 退信提示："SDN14"
• 退信提示："SDN13"
• 退信提示："SDN4"
• 退信提示："SDN3"
• 退信提示："SMTP error, RCPT TO: 550 Mail from XXXX refused"
• 退信提示："554 Service unavailable"