transport.template is not working in 2.2.3

[Klaus.Rumpp at antec-online.de]

we were using transport.template as described in :
http://www.kolab.org/pipermail/kolab-users/2007-October/006820.html
for

two kolab-systems on different places, with no directly connection over the 
internet (no open port's), but proper for the same domain (example.com), must 
two-way mail exchange.

It worked flueless for the last 2 years with kolab 2.2.0

But after update to 2.2.3, we´ll always get :
" 5.1.1 <user2 at doamine.tld>: Recepient address rejected : User unknown 
in local recipient table. Please ... "

What might cause the problem ?