Hello,
I'm new to this list so I apologise if this is a FAQ. I use exim on
Debian sid with more or less standard Debian config. It works fine
except that I've just discovered I can't route to hosts on local network
(I have have a typical 192.168 network behind nat). I get Unroutable
Address. I can't fathom the reason, but what seems to be happening is
that exim is looking up MX for local domain successfully - it then
successfully resolves host for given mail server then, for some reason
it looks up unqualified hostname - DNS refers this latter to root
servers and returns failure. This happens 3 times and then message
bounces. No attempt is made to resolve address of destination host or
to contact destination host with SMTP.
What it seems like is exim is trying to relay to itself in order to
route to local hosts and ends up in a loop. However exim could also be
responding to DNS lookup failure.
I've fiddled with local_domains, relay_to_domains, relay_from_hosts and
a few other things but cannot change this behaviour.
So I don't really know if this is a DNS or exim config issue - maybe
someone can give me a clue.
Thanks
Dick