[Exim] Multiple Mailservers with one domain

Hi there,

I want to install a second mail server for a client. They have a single
registered domain.
The sattelite branches are connected via a 64k permanent leased line. The
problem we are finding
is that the congestion accross the line is quite high since all the users
download mail and send mail
from our central offices Installing a dditional servers at the regions and
controlling the delivery seems to
be the answer to our problems. The users are using Win 98 and Outlook 97.

Here is the idea: The users send mail to the local Linux server running
Exim. It will determine whether the
recipient is local or not and then it will deliver accordingly. If the user
is not local it will forward the mail to the
Head Office "Smart Host" for delivery.

Problem: Our local server does know about other users in our domain so it
will reject all mail destined for
"unknown" users to the sender. How do I enable this without changing the
servers name?

Our domain is "schenker.co.za"
Our Head Office server is called mail.schenker.co.za
Our satellite server is dbn-pop.schenker.co.za

dbn-pop.schenker.co.za only accepts mail for schenker.co.za so our users
dont get confused by mail arriving for
user@??? and all appears the same. Our server:
dbn-pop.schenker.co.za uses fetchmail to fetch mail for the users so
incomming mail can be scheduled.

If I have a user at our head office called user1 and another at a satellite
called user2 how do I get Exim to allow a delivery to user1@???
from user2@??? since user1 is not known in Exims configuration?


Any assistance would be greatly appreciated.

Kind regards
Gary