Hi, Some time ago a changed the hostname of my ISPConfig 2 server. Now, after I updated ISPConfig the mailserver keeps forwarding mail to the old domain followed by a host not found. Host or domain name not found. Name service error for name=olddomain.xxxxx type=AAAA: Host not found I looked at /etc/postfix/main.cf, changed and restarted Postfix. No luck. I added the old hostname to /etc/hostname. No luck. How can I fix this?  Fixed it by adding the old domain to: /etc/postfix/local-host-names This looks more like a work around then a fix but it works.