能收到邮件但是发不出去

错误日志如下

Nov  4 20:32:21 localhost postfix/cleanup[4853]: warning: 51CCA2E129: virtual_alias_maps map lookup probl         em for xxxx@gmail.com
Nov  4 20:33:21 localhost postfix/pickup[4851]: 587A12F5F5: uid=0 from=
Nov  4 20:33:21 localhost postfix/cleanup[4853]: warning: connect to mysql server localhost: Can't connec         t to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

原因是之前配置了基于mysql的地址映射

virtual_alias_maps = mysql:/etc/postfix/mysql-alias.cf

当一些在chroot环境中运行的postfix组建试图通过/var/run/mysqld/mysqld.sock连接数据库时就报错了，在master.cf里禁用smtp,rewrite,cleanup的chroot即可

smtp      inet  n       -       n       -       -       smtpd
rewrite   unix  -       -       n       -       -       trivial-rewrite
cleanup   unix  n       -       n       -       0       cleanup

#这是一种不安全的fix方法，另一种解决方法是修改my.conf同过3306端口访问mysql，也可以解决问题。