I've been running a few things through my head about setting up a mailing list manager with 2 MTAs. At first I thought I'd have to install the service on both MTAs. Then I realized that wouldn't work becase of archiving, and a few other issues. Now I believe it is possible to implement on one server. I just wanted to run my thoughts by the Zimbra Gurus first for their impression.

MTA1 -- perfered MTA, holds mailing list management services
MTA2 -- nothing special

If I setup a catchall for the domain:
$ zmprov md example.com zimbraMailCatchAllAddress @example.com
$ zmprov md example.com zimbraMailCatchAllForwardingAddress @example.com

Then setup mail routing:
$ zmprov md example.com zimbraMailTransport smtp:mail.example.com

This would mean that everything unknown to Zimbra (including mailing lists) that is sent to the secondary MTA would then get forwarded to the primary. The primary would then be able to either bounce the message or expand the possible mailing list.

Or would this mean that every piece of mail is sent to the primary. If I understand prior messages it would mean the former.

Then by following the Zimbra Mailman guide I should in theory have a working mailing list system correct?