[Obm] OBM with external postfix, etc, etc

[Reno Wijoyo]

Hi

I'm new to OBM and are still considering if I'm going to go with OBM or 
SOGo. I need to know if OBM able to work with existing:
1. postfix
2. dovecot
3. dovecot SASL or SMTP authentication
4. external jabber server

I need to know if OBM can work with existing external system or force to 
use its own postfix, etc.

Rgds,
Reno W.