Forwarding subdomain to another host

[juresimsic]

Hi,
I'm trying to set up zimbra to forward all @sub.domain.com mails to another system. I have a split server instalation with MTAs on separate servers. The MX records for @domain.com and @sub.domain.com point to these MTAs, but I want it to forward @sub.. elswhere.

I've tried to set up special postfix transport maps (as in Transport Table for external servers - Zimbra :: Wiki) but it didn't work. I've also tried to do it as a secondary mta (as in http://www.zimbra.com/forums/adminis...nce-print.html) with the catchall forwarding, but it seems the mail wants to be delivered locally..

As I can see in the logs, it gets in, it gets sent to amavis&co (relay=127.0.0.1[127.0.0.1]:10024), when it gets back in the queue, I'd expect it to be send via the transport rule, but it seems to be stuck for local delivery (relay=none)

I have my postfix transport maps set up:
$ zmlocalconfig postfix_transport_maps
postfix_transport_maps = hash:/opt/zimbra/postfix/conf/transport,proxy:ldap:/opt/zimbra/conf/ldap-transport.cf

$ cat /opt/zimbra/postfix/conf/transport
sub.domain.com :[1.2.3.4]

but it seems to be ignored.. What is the right way to do this?

Thanks
Jure