- 企业邮箱邮件被收件方拒收，收件方返回退信说明 “550 Mailbox not found”
- 企业邮箱退信提示：“UnKnown can't find abc.com： Non-existent domain”
- 企业邮箱退信提示：“SMTP error，DOT：550 abc.com has no A,AAAA,,or MX DNS records…”
- 企业邮箱退信提示：“SMTP error, RCPT TO：553 5.7.1 sorry, that domain isn't in my list of allowed rcpthosts (chkuser)”
- 企业邮箱退信提示：“SMTP error, RCPT TO：550 No such domain at this location”
- 企业邮箱退信提示：“501 5.7.1 Sender refused by the DNSBL zen.spamhaus.org.”
- 企业邮箱退信提示：“SMTP error, MAIL FROM：553 SPF check refused(softfail)”
- 企业邮箱退信提示：“Host abc.com(xxx.xxx.xxx.xx) RCPT TO said 421 Refused. You have no reverse DNS entry. Contact abuse@abc.com for details”
- 企业邮箱退信提示：“SMTP error, DOT： 554 5.7.1 This message has been blocked because the return email domain is invalid.(failed to obtain DNS record for domain abc.com)”
- 企业邮箱退信提示：“SMTP error, RCPT TO： 550 [PERMFAIL] abc.com requires valid sender domain”
- 企业邮箱退信提示：“No MX or A records for abc.com”
- 企业邮箱退信提示：“MAIL FROM： 550 5.0.0 Mail rejected due to possible SPAM。”
- 企业邮箱退信提示：“Host abc.com(xxx.xxx.xx.xx) MAIL FROM said 451
- 企业邮箱退信问题处理方式
- 企业邮箱退信提示：“RCPT TO：550 Disabled.”
- 企业邮箱退信提示：“SMTP error, MAIL FROM：553 sorry, your envelope sender domain must exist”
- 企业邮箱退信提示：“550 5.7.1 Recipient not authorized, your IP has been found on a block list”
- 企业邮箱退信提示：“delivery temporarily suspended：connect to mail.abc.com[xxx.xxx.xx.xx]：Connection timed out”
- 企业邮箱发往aol.com收到的退信。
- 企业邮箱退信提示：“550 abc@domain：mailbox limit exceeded (inreply to end of DATA command)”
