Mailing Lists w/ 2 MTAs

rsharpe · Post by **rsharpe** » Tue Mar 14, 2006 12:24 pm

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?

14319KevinH · Post by **14319KevinH** » Tue Mar 14, 2006 12:53 pm

I think you could just set the relay host on MTA2 to point to MTA1 so all unresolved messages will get sent to MTA1.

rsharpe · Post by **rsharpe** » Tue Mar 14, 2006 1:09 pm

Wouldn't that only work for mail going inside out? Because the way I interpt what you saying is that I should set the "Relay MTA for external delivery". What about external mail being set to the mailing list? That wouldn't work... would it?

14319KevinH · Post by **14319KevinH** » Tue Mar 14, 2006 1:26 pm

Yeah your right. You'd need to do the smtp: like you referred to above for *each* mail list address. So not at the domain level but on each mail list entry. Otherwise split domain will not work. Sorry about the confusion.

rsharpe · Post by **rsharpe** » Tue Mar 14, 2006 2:02 pm

So for each mailing list that I have I must create the user in Zimbra as well?
zmprov ca mailman@example.com

zmprov ma mailman@example.com zimbraMailTransport smtp:mail.example.com.
---------------------------------------------------
A couple of concerns: (Note: Both MTAs are Zimbra MTAs)

1. If mail destined for a mailing list is sent to MTA2 is it going to route the mail before trying to deliver it to a mail box.

2. If mail destined for a mailing list is sent to MTA1 is it going to initiate a mail routing loop?
The reason I ask these questions is because both MTAs will be referring to the same LDAP server. My first thought is everything should be fine, but just to be 100% I thought I would ask. Thank you.