[Mailman-Users] virtually hosted domains

[temple at is.asu.edu]

How do I force the mail coming from mailman to the users to use a virtual
domain rather than the host machines real name?  For example; say I have a
machine with the name realhost.org.  On it I am virually hosting the name
virthost.org. I want to run a list called test on the virthost.org.  This
all works find. Users can send mail to test at virthost.org and all is well.
But when they receive mail from the list, it shows a TO: line that
indicated realhost.org i.e

From: joeshmow at blablabla.com
To: test at realhost.org

If a user replies to this, the reply address shows up as realhost.org. It
still works of course, but it isnt' pretty. I want it to show up as
TO: test at virthost.org.

I am using sendmail on Linux.  In my case, virthost.org would show up in
the DNS as an alias:

>nslookup virthost.org

Name:    realhost.org
Address:  ###.###.###
Aliases:  virthost.org

I have also put virthost.org in the "Host name this list prefers" element
of the test list.  

Thanks

-Temple