From checking /var/log/maillog, it seems that the server doesn't seem to recognize its own hostname anymore. I'm getting this error:
Nov 18 17:42:38 z postfix/error[22507]: 9C43B12C13A4: to=<user@zimbra.mydomain.com>, relay=none, delay=0.05, delays=0.03/0/0/0.01, dsn=4.4.3, status=deferred (delivery temporarily suspended: Host or domain name not found. Name service error for name=zimbra.mydomain.com type=A: Host not found, try again) |