[exim] Exim - SA - Exchange

Hi

I have to setup an incoming gateway that receives mail filters it and
then forwards this onto the exchange cluster that is on out LAN - Is
there a good how-to on this, i will be using RHEL4 and so the package
option is best for me if possible. I have used SA and Postfix in the
past so its just the exim configuration and also plugging SA and Exim
together that i need help with.

thanks