Hello guys,

I am a little confused about the configuration of "SMTP host" when I am installing a Zimbra mailbox server and "MTA Auth host" when I am installing a Zimbra MTA Server with a multi-server setup environment.

Installing a Zimbra mailbox server:
2) zimbra-store: Enabled
... ...
******* +SMTP host: UNSET

Installing a Zimbra MTA Server:

3) zimbra-mta: Enabled
+MTA Auth host: UNSET

I have multiple mailbox servers and MTA servers and originally I believe they have a "multi to multi" relationship. For an incoming message, MTA gets the "ZimbraMailHost" from LDAP during the authentication and routes the inbound message to the corresponding mailbox server which hosts the mailbox for that account.

Anyone please clarify:

1, What are "SMTP host" and "MTA Auth host" used for?
2, How should I configure them with a multi-server installtion?

For "MTA Auth host", regarding to the guide, it is said "MTA Auth host. This is configured automatically if the MTA authentication server host is on the same server, but must be configured if the authentication server is not on the MTA. The MTA Auth host must be one of the mailbox servers."

Also a thread said "Previously, it assumed that the auth host was the localhost - which caused problems during multi-host installs. So, the answer to how it worked before was "poorly". " (http://www.zimbra.com/forums/users/1...auth-host.html)

Sorry I am not quite clear with these answers and could anyone please clarify more precisely? Thank you.