Connect to private/auth failed: No such file or directory . postfix

sudo tail -f 10 /var/log/maillog
warning: SASL: Connect to private/auth failed: No such file or directory
fatal: no SASL authentication mechanisms

查看：/etc/dovecot/conf.d/10-master.conf
找到 unix_listener private/auth
修改为：unix_listener /var/spool/postfix/private/auth
unix_listener /var/spool/postfix/private/auth { 
      mode = 0666 
      user = postfix 
      group = postfix 
    } 

然后 sudo systemctl restart dovecot