postfix: mail forwarding for domain if user unknown

[Alain Spineux]

On 9/26/07, Thomas Nintemann <t.nintemann at medial-networks.de> wrote:
> 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.

If fact both kolab server are speaking together but they use some
intermediate server(s) and
also pop3 protocol (fetchmail)

> 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.

This is any SMTP server different of the kolab server itself that will
accept to relay email to
its final destination, where (the final destination) fetchmail of the
other server will download them.
Usually your ISP provide you such kind of 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,

a "fake" kolab server, but a real SMTP server anyway !

> he sends the mail to the ISP's mailserver from the
> smarthost entry.

Yes If the "fake" server you used is the same as the smarthost you
have setup, but...
Sorry for using the word smarthost that is already used in kolab GUI.
For me smarthost means any SMTP server that will accept to relay all
your emails using only DNS MX pointers for routing, without doing any
filtering, address rewriting, or local delivery.

> 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...

Yes

>
> Thanks
>
> Thomas
>
> _______________________________________________
> Kolab-users mailing list
> Kolab-users at kolab.org
> https://kolab.org/mailman/listinfo/kolab-users
>


-- 
Alain Spineux
aspineux gmail com
May the sources be with you