postfix: mail forwarding for domain if user unknown

[Thomas Nintemann]

Am Mittwoch, 26. September 2007 17:47:39 schrieb Thomas Arendsen Hein:
> * Thomas Nintemann <t.nintemann at medial-networks.de> [20070925 20:13]:
> > > Can I reach port 110 and 25 of the other server ?
> > > Are they reachable from the internet ( port 25 and 110) ?
> >
> > No, the both server cannot communicate directly together and they have no
> > open ports that are reachable from the Internet.
>
> Usually I would have said that you can use a transports entry for
> these users or create Kolab accounts with a fake kolabHomeServer
> entry pointing to the non-Kolab server, but for all this the Kolab
> server has to be able to communicate with the second server on port
> 25.
I think you mean that the fake kolabHomeServer is the ISP (relay) smarthost
that is known by the kolab-server and not the second kolab-server.
>
> But how do you think the mail should be passed to the other side if
> the second server isn't reachable from the first?

Both kolab-servers have a fetchmail running in non multidrop mode and they get 
the mails from the ISP via pop3.
If one of the kolab-servers has user2 at example.com as a user with a fake 
kolabHomeServer entry, he sends the mail to the ISP's mailserver from the 
smarthost entry.
Then the other kolab-server get's the email for user2 at example.com with 
fetchmail and deliver the mail for the real mailbox.

Is that accurate? Please correct me if i think wrong...

Thanks

Thomas