postfix: mail forwarding for domain if user unknown: solved

[Thomas Nintemann]

Am Mittwoch, 26. September 2007 20:35:59 schrieb Thomas Nintemann:
> OK, thanks very much for you advertence to my problem with the "one domain
> on two kolab-systems without direcly connection".
>
> On Friday i get a chance to test the scenario and i will post the outcomes
> here to the list.
>

Hello,
the problem was:

Two kolab-systems on different places, with no directly connection over the 
internet (no open port's), but proper for the same domain (example.com), must 
two-way mail exchange.
Because both kolab-systems have several mailboxes that must be able to 
communicate together over an ISP relay server.
Example: kolab-system1 has user1 at example.com and user2 at example.com.
Kolab-system2 has user3 at example.com and user4 at example.com.

here is my field report about the problem:

What you need to get it work:
A ISP with the whole mailboxaccounts for a domain.
The ISP mailserver must be able to let you relay mail's to the ISP via smtp 
and fetch mail's via pop3. 

The both kolab-servers simply needs a installed fetchmail, that is running in 
non multidrop mode and fetch the e-mail's from the ISP for his kolab-server 
mailboxes.
Example: On kolab-system1 fetch  user1 at example.com and user2 at example.com.
On kolab-system2 fetch  user3 at example.com and user4 at example.com.

As recent the both kolab-systems must now, that the users, that email's for 
users that have no local mailbox for the domain, must be send out to the 
relayhost of the ISP. This can simply be done with the transport.template in 
the templates folder of each kolab-system.
Simply put the email adresses of the users that are life on the other 
kolab-system in each kolab-system transport.template in this format:
user1 at example.com smtp:[your.isp.smarthost].
then make a kolabconf, to activate that.
Example: kolab-system1 needs user3 at example.com and user4 at example.com in 
transport.template and kolab-system2 needs user3 at example.com and 
user4 at example.com in transport.template.

But be attentive:
This setup only works, if you want to have simply mailexchange!
You are not able, for understandable reasons,  to share folders over that 
setup!

If you want to have mailgroups for the both kolab-systems, you must 
create kolab-users with webadmin-tool for every mailadress in 
transport.template for each kolab-system and give them the ISP relay server 
as kolabHomeServer.
 
That's it.

Thanks again for the nice kolab-system and Alain Spineux for his notice about 
my problem.

Thomas