dns mx question

[Ben Luey <lueyb@gridley.ACNS.Carleton.edu>]

We have a registered domain that we use for e-mail. I want e-mail send
from the intranet to go to the server and be processed without triggering
our internet link (dial on demand), but don't want to be a master dns for
the domain name since the web site and stuff has a real internet addresses
and is contorled by other people. I just want to have hearingsociety.org
have a local MX record and all other dns requests handled by the
forwarders.

I currently have in my domain.hosts:

@               IN SOA        hearing.org. server.hearing.org.  (
                              1997080600    ; serial number
                              10800         ; refresh rate (3 hours)
                              1800          ; retry (30 minutes)
                              1209600       ;  expire (2 weeks)
                              604800 )      ;  minium (1 week)
                MX 5       server.hearing.org.
                NS         server.hearing.org.
#                NS         hearing.org.
hearingsociety.org.    MX 3 server.hearing.org.
server          A          192.168.1.1
finance          A          192.168.1.211

giving hearingsociety.org a MX record; however, since in /etc/named.conf,
domain.hosts is only in the zone for hearing.org 

zone "hearing.org" {
        type master;
        file "domain.hosts";
};

This works, but when our internet access stopped, local mail would not get
delivered I think because the dns lookup somehow needed outside access to
resolve the MX on hearingsociety.org -- when I shut down named and added a
line to the /etc/hosts it fixed the problem, but that messes up website
dns lookups.

Any ideas?

Thanks,

Ben