Question regarding delivery from Postfix via LMTP proxy

[Vlad Sedov]

Hello,

I'm using Postfix with Dovecot 2.3.13, and trying to get LMTP proxy to 
work for authentication and delivery in the following scenario:

Incoming Mail  -> Postfix (server A) -> LMTP to Dovecot (server A) -> 
LMTP to Dovecot (server B)

I'm using MySQL for authentication.

I've created a user on both server A and server B, test at domain.tld
On server A, host parameter in password_query for test at domain.tld is set 
to server B's address, and proxy_maybe is enabled.

Delivery and authentication to Server A works fine.
Authentication and IMAP proxy to server B works fine as well. I can 
connect to IMAP on server A with credentials for test at domain.tld and 
access the maildir on server B. This works surprisingly well, and is 
about half the battle for me..

What I can't figure out, is how can I get Postfix to deliver mail using 
LMTP via server A to server B.. Currently, mail still gets delivered to 
the user's maildir on server A.

Is this possible with Dovecot alone, or do I need to use another method 
to get messages to hop to server B via server A?


Any help would be appreciated..

cheers,
Vlad