我有一台安装了 CentOS 5.6 的服务器。它有 exim + dovecot + mysql + roundcube 的邮件服务器。
我的日志文件 /var/log/exim/main.log 已经达到 3 GB 并且还在不断增大。它包含以下条目：
2013-03-12 18:09:42 1UEaWr-0003VI-Ts == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:42 1UEIcr-0005k3-Mc == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:42 1UE8ro-00011h-8S == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:42 1UEtDl-0006jP-8h == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:43 1UEipX-0001Ub-5z == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:43 1UESyw-0003mv-E0 == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:43 1UEA9c-0005gO-71 == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:43 1UE7rt-00074q-2G == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:43 1UEkev-0004od-HA == [email protected] R=dnslookup defer (-1): host lookup did not complete
2013-03-12 18:09:43 1UEsBj-0002dM-Mt == [email protected] R=dnslookup defer (-1): host lookup did not complete
我知道这是因为 mail.mydomain.com 根本不是 FQDN 或真正的域名。但它从何而来？我检查了 /etc/exim/exim.conf 和 /etc/ 中的每个文件，但找不到这个域字符串。此外，我检查了 vexim 数据库的表 - 没有结果。我该如何更改它？
然后，当我尝试发送邮件时，我在日志中收到此错误（我已经替换了真实的邮件和 IP 地址）：
2013-03-12 18:13:30 1UFJGl-0004c9-2X == [email protected] R=dnslookup T=remote_smtp defer (-45): SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=1406: host mail2.to.com [x1x.x1x.x1x.x1x]: 451 4.1.8 Sender address <[email protected]> domain does not resolve
2013-03-12 18:14:34 1UFJGl-0004c9-2X SMTP error from remote mail server after RCPT TO:<[email protected]>: host mail.to.com [x1x.x1x.x1x.x1x]: 450 4.7.1 Client host rejected: cannot find your hostname, [x2x.x2x.x2x.x2x]
我认为这个问题的根源是一样的。但找不到解决方案。我假设我的问题是用exim替换默认的FROM字段（[电子邮件保护]）类似[电子邮件保护]
有什么帮助吗？谢谢。
答案1
您没有正确设置 IP 地址的反向 DNS（PTR 记录）。
为您的 IP 地址设置一个 PTR 记录，该记录解析为有效的主机名，其 A 记录解析为相同的 IP 地址。