That's the SPF record, and shouldn't be confusing Postfix. You could try removing it temporarily (but you'll want it back, eventually, and you'll want to add the Google outgoing servers if you use those for outgoing mail from your domain).

Hi Joe,

A friend finally pointed me in the right direction to solving the mystery!

The solution was to add MX records to the local BIND server, that point to the remote server that's meant to handle the mail:

daimon.ch. IN MX 10 aspmx.l.google.com.
daimon.ch. IN MX 20 alt1.aspmx.l.google.com.


In the absence of the MX records, Postfix seems to somehow think that because the www ip is local, so is MX, rather than look up the MX entries in the registrar's name server (which did already have the above definitions).

Many thanks for your help on the way!
Robert