master/slave setup via VPN?

[Thorsten Schnebeck]

Hi,

I'm trying to use a Kolab-2.2 master/slave multi-domain setup with one special 
detail: The smtp communication is only via vpn available.

Lets create an example:

master.domain1.com: IP 1.2.3.4 + VPN 10.10.10.1
slave.domain2.com: IP 4.3.2.1 + VPN 10.10.10.2

on master I have users of the mail-domains maildomain1.com, maildomain2.com
on slave I have users of the mail-domains maildomain2.com(!), maildomain3.com

master collects all mails of all 3 maildomains.
If the users has its mailbox on slave if see something like this in the master 
postfix log:

connect to slave.domain2.com[4.3.2.1]: Connection timed out (port 25)
Jul 18 21:48:39 master <info> postfix/smtp[5227]: 72668274971: 
to=<test at maildomain3.com>, relay=none, delay=3350, delays=3320/0.06/30/0, 
dsn=4.4.1, status=deferred (connect to slave.domain2.com[4.3.2.1]: Connection 
timed out)

So, I need a config that transfers the Std-IP of slave to its VPN-IP but only 
for postfix. IMHO I can not use transport.db cause I have users of 
maildomain2.com on master _and_ slave.(?)

Suggestions?

Bye

  Thorsten