Migrating to Postfix+Kolab

[AnViar]

I install kolab2 with standart templates. But I have old mail-server and momentary migrating impossible.
in main.cf I wrote:
fallback_relay = [<ip-old-server>]:25
fallback_transport = smtp:[<ip-old-server>]
It's meen: if user not avalable in kolab-server, then mail try to deliver to old-server.
But all mails bounced on kolabmailboxfilter.
Jul  2 17:57:58 black postfix/pipe[14316]: BAFA12314FF: to=<user@mydomain.ru>, relay=kolabmailboxfilter, delay=0, status=bounced (service unavailable. Command output: Failed to set recipient: Mailbox unknown.  Either there is no mailbox associated with this name or you do not have authorization to see it. 5.1.1 User unknown, code 550 )
If I comment string
#mailbox_transport = kolabmailboxfilter
all mails will redirect to old server.
How to solve this problem?
P.S. sorry for english 

[Gunnar Wrobel]

Hm, I don't know the answer to this question without looking at the postfix documentation. But I am absolutely certain that this can be done with postfix.

fallback_relay probably gets called really late and once you get into the kolab_mailboxfilter processing you have a problem. You should try to solve the redirection problem using the configuration for the trivial-rewrite process (http://www.postfix.org/trivial-rewrite.8.html). Maybe something like the simple rewrite comand could solve your problem.