dovecot - Oct 2007 - Dovecot, postifx, virtual domains and deliver, what about luser_relay/fallback_relay?

I've read documentation (obviously not the right parts) and googled, but 
I can't seem how to solve this simple problem:

I have a machine running postfix/dovecot and using virtual domains, 
delivery happens with dovecot's LDA. I also have an Exchange machine 
that I have to house some of the users of a given domain.

How can I tell either postifx in general or dovecot's LDA that whatever 
specific user that cannot be found in the virutal setup can be pawned 
off to a given relay-server which will sort it out?

-A

Alexander Hoogerhuis wrote:
> I've read documentation (obviously not the right parts) and googled,
but
> I can't seem how to solve this simple problem:
> 
> I have a machine running postfix/dovecot and using virtual domains,
> delivery happens with dovecot's LDA. I also have an Exchange machine
> that I have to house some of the users of a given domain.
> 
> How can I tell either postifx in general or dovecot's LDA that whatever
> specific user that cannot be found in the virutal setup can be pawned
> off to a given relay-server which will sort it out?
> 
This is for postfix. The answer depends on which addresses would be
accepted (not rejected nor bounced) by the relay-server. In short, will
it accept all addresses? would I get a bounce if I send to
arbitrayaddress at domain.example?



followup on the postfix users list.