Am Sat, 08 Mar 2014 08:33:14 +0100 schrieb Paul Klos <kolab at klos2day.nl>: > I have > > relayhost = smtp.example.org This works if it has a MX record in DNS. If not, then add square brackets around it: relayhost = [smtp.example.org] http://www.postfix.org/postconf.5.html#relayhost With brackets it uses the common A record.