Does it show just offline or is it not working? Check the mail.log for errors and try to restart postfix.
It's not working Code: [root@vps ~] [root@vps ~]# service postfix status master dead but pid file exists [root@vps ~]# service postfix start Starting postfix: [ OK ] [root@vps ~]# service postfix status master (pid 28698) is running... [root@vps ~]#
Strange. Is this the only service that fails, or do you have similar problems with e.g. dovecot or apache or mysql? One thing that you can try is to install monit to start postfix automatically when it fails.