Richard Kettlewell wrote:
[SNIP]
Sounds like a DNS problem to me; make sure that's all working properly before trying to do mail.
I don't know about Exim but some MTAs (and some other applications) do not look at /etc/hosts for some/all DNS lookups (which is hardly surprising given that it's impossible to encode an MX record in a hosts file). For these applications to work you must have your hostnames in DNS as well (or instead).
If you go the DNS route, I suggest you look at djbdns. Set up dnscache on your internal NIC, and tinydns on 127.0.0.1. That way, dnscache (the resolver) will query tinydns (the name server) for resolution of internal names, and will go to the outside world (direct to the root servers, actually) for anything else. It's not trivial, but it's not so hard either.
Cheers, Laurie.