退信

• 退信提示："not our MX service client"
• 退信提示："is not my user"
• 退信提示："No Such User Here"
• 退信提示："no mailbox here by that name"
• 退信提示："mailbox unavailable"
• 退信提示："Invalid Address"
• 退信提示："User unknown in local recipient table"
• 退信提示："the account is disable"
• 退信提示："no such user"
• 退信提示："rcpt account is invalid"
• 退信提示："recipients are invalid"
• 退信提示："The account does not exist"
• 退信提示："Account Unavailable"
• 退信提示："Invalid character"
• 退信提示："no mailbox by that name"