退信

• 退信提示："User not local"
• 退信提示："This user doesn't have a yahoo"
• 退信提示："user not found"
• 退信提示："unknown user"
• 退信提示："Local no so user"
• 退信提示："no valid recipients"
• 退信提示："Unrouteable address"
• 退信提示："user not exist"
• 退信提示："User suspended"
• 退信提示："user unknown"
• 退信提示："Not our Customer"
• 退信提示："Invalid recipient"
• 退信提示："Invalid sender"
• 退信提示："Recipient unknown"