Upgrade failed

[Tripple]

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?

[edit]
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.

[till]

Make sure that you have set the new hostname also in /etc/mailname in case that this file exists on your server.

[Tripple]

Never heard of that file.
Indeed this was the file with the old hostname. thx.