[Mailman-Users] domain name alias, two domains on one MM?

[James Nightly]

It doesn't work for some reason. I can see emails routed to the new domain,
but there is an "unroutable address" error in the logs.

Our old lists.old_name.org is pointing to lists.new_name.org. MM lists
names are same, the only change is in the domain (lists.old_name.org vs
lists.new_name.org -- or mailman at lists.old_name.org vs
mailman at lists.old_name.org).

However, when I SMTP test for lists.old_domain.org I get a response from
lists.new_domain.org, like this:

SMTP test for lists.OLD_DOMAIN.org

Connecting to 69.9.9.9 *(obfuscated)

220 lists.NEW_DOMAIN.org ESMTP Exim 4.84 Wed, 17 Sep 2014 08:02:03 -0700
[5678 ms]
EHLO MXTB-PWS3.mxtoolbox.com
250-lists.new_name.org Hello mxtb-pws3.mxtoolbox.com [64.20.227.133]
250-SIZE 52428800
250-8BITMIME
250-PIPELINING
250 HELP [655 ms]
MAIL FROM: <supertool at mxtoolbox.com>
250 OK [655 ms]
RCPT TO: <test at example.com>
550 relay not permitted [655 ms]

MXTB-PWS3v2 8440ms

ping lists.old_domain.org reply from 69.9.9.9 OK
ping lists.new_domain.org reply rom 69.9.9.9 OK