After some analysis, I believe I might approach this by:
- Add a new MX record for lists.mydomain.com to point to the existing A record for lists.mydomain.com.
- Create a DL in the new mail environment that will have one recipient which is the name of the list @lists.mydomain.com.
This should cause the new mail server to forward any mail sent to
my @lists.mydomain.com to the mailman server where it will be broadcast.
The only trouble is, the web panel, wiki and this message board do not appear to offer any details as to how to proceed along this path.
Anyone have a suggestion? I'll create a support ticket and will report back here.