[Dovecot] proxy (director) and destination ports

[Oliver Eales]

Hello,

i am delivering Mail from postfix via LMTP to dovecot. I am using the 
director also for LMTP.
As long as i connect to the dovecot LMTP TCP socket from postfix 
everything is working.

postfix main.cf: virtual_transport= lmtp:localhost:30025

But when i try to  switch to the local socket

postfix main.cf: virtual_transport = lmtp:unix:private/dovecot-lmtp

The dovecot proxy tries to connect to the backend server port 0 which is 
obviously not working.
The proxy always seems to connect to the same port on the backend as it 
was accessed itself.

Nov 24 14:55:09 auth: Debug: master out: PASS   1       user=1000000000030      proxy
Nov 24 14:55:09 lmtp(7330): Debug: auth input: user=1000000000030 proxy host=10.1.1.151 proxy_refresh=450
Nov 24 14:55:09 lmtp(7330): Error: lmtp client: connect(10.1.1.151, 0) failed: Connection refused
Nov 24 14:55:11 director: Error: director(15.189.34.59:13459/out): connect() failed: Connection refused


Is it possible to set the destination port (30025) of the backend server 
to the proxy ?

Regards,
Oliver