[TriLUG] Forcing user at host@host routing in sendmail?

[Rodent of Unusual Size]

I frequently have to send mail to people in a domain
inside a firewall which doesn't export the internal DNS.
Sending mail to <user at host.foo.bar> from outside the firewall
will always fail because host.foo.bar isn't in the global
DNS.  However, if I explicitly route it through a system
on the firewall 'fence', <user at host.foo.bar@fence.foo.bar>,
which knows about both the internal and external DNS,
all works well.

Is there any way to tell sendmail that all *@*.foo.bar
addresses need to be rewritten to *@*foo.bar at fence.foo.bar?
It *might* be hackable into the normal rulesets, but does
anyone know if there's a special provision for this?  Or
where better to ask?

Ta!
-- 
#ken	P-)}

Ken Coar, Sanagendamgagwedweinini  http://Golux.Com/coar/
Author, developer, opinionist      http://Apache-Server.Com/

"Millenium hand and shrimp!"