[Exim] Exim As A Mail Hub

I am currently setting up exim to run as a mail hub for our site. I
currently have exim delivering to only one mail server successfully,
but would like it to deliver to multiple mail servers.

There are no user accounts on the exim machine, so all address
look up's will need to go though an alias database.

I currently have the exim configuration file set as follows:

local_domains = mailhub.pcfe.co.uk:pcfe.co.uk

I am using pcfe.co.uk for testing and have all mail for the domain
delivered to exim through an MX record of 0 in the DNS.
Mailhub.pcfe.co.uk is the exim machine.

This treates all mail being sent to pcfe.co.uk as local to the exim
machine. However, because this machine does not have any user
accounts, delivery fails.

My question is how do I look up the local part of the address from a
database to find the delivery address so that the messages can be
routed to other mail servers?

Thanks for any help and assistance.


Gordon Carn BSc
Postmaster
Plymouth College of Further Education
Kings Road
Devonport
Plymouth
Devon
PL1 5QG
England

Tel: +44 (0)1752 305355