抱歉！以上报错信息是QQ邮箱发送邮件到iredmail失败后的退件提示的信息，不是iredmail的日志信息。显然是被自己的邮件服务器拒绝了。

贴上maillog昨天相关日志内容（***@***.***代表本地的邮箱，***@sina.com代表新浪的邮箱，***@qq.com代表腾讯邮箱。172.18.81.20是公网访问到本地的统一的映射地址。vm202是邮件服务器的主机名。）

Jul 20 11:49:27 vm202 policyd: connection from: 127.0.0.1 port: 39930 slots: 1 of 2044 used Jul 20 11:49:27 vm202 policyd: rcpt=167, blacklist=block, host=172.18.81.20 (unknown), from=***@sina.com, to=***@***.***, size=1140 Jul 20 19:49:27 vm202 postfix/smtpd[14448]: NOQUEUE: reject: RCPT from unknown[172.18.81.20]: 554 5.7.1 : Recipient address rejected: Policy Rejection- Abuse. Go away.; from= to= proto=ESMTP helo=Jul 20 19:49:27 vm202 postfix/smtpd[14446]: disconnect from unknown[172.18.81.20]Jul 20 19:49:27 vm202 postfix/smtpd[14448]: disconnect from unknown[172.18.81.20]Jul 20 19:52:47 vm202 postfix/anvil[14449]: statistics: max connection rate 2/60s for (smtp:172.18.81.20) at Jul 20 19:49:25Jul 20 19:52:47 vm202 postfix/anvil[14449]: statistics: max connection count 2 for (smtp:172.18.81.20) at Jul 20 19:49:25Jul 20 19:52:47 vm202 postfix/anvil[14449]: statistics: max cache size 1 at Jul 20 19:49:24Jul 20 19:52:58 vm202 postfix/smtpd[14483]: connect from unknown[172.18.81.20]Jul 20 11:52:59 vm202 policyd: connection from: 127.0.0.1 port: 41430 slots: 0 of 2044 used Jul 20 11:52:59 vm202 policyd: rcpt=168, blacklist=block, host=172.18.81.20 (unknown), from=***@qq.com, to=***@***.***, size=0 Jul 20 19:52:59 vm202 postfix/smtpd[14483]: NOQUEUE: reject: RCPT from unknown[172.18.81.20]: 554 5.7.1 : Recipient address rejected: Policy Rejection- Abuse. Go away.; from= to= proto=SMTP helo=Jul 20 19:52:59 vm202 postfix/smtpd[14483]: disconnect from unknown[172.18.81.20]Jul 20 19:54:47 vm202 postfix/smtpd[14493]: connect from unknown[172.18.81.20]

老大分析正确！的确是“Policy-daemon”的提示信息，请给下一步的提示，谢谢了！