外域入信失败原因

• • 550 Sender domain is a local domain.
• • 550 Connection denied
• • 550 Mail is rejected by recipients.
• • 550 Mailbox unavailable or access denied
• • 501 Bad address syntax
• • 552 Message too large
• • 550 Mailbox not found
• • 550 Mail content denied
• • 550 Ip frequency limited
• • 550 Domain frequency limited
• • 550 Sender frequency limited
• • 550 Connection frequency limited