[Exim] Minimal configuration to forward all mail from one ma…

I've been trying to figure this out for an hour now, but since I'm
apparently barking
up the wrong trees I'm ready to advertise my ignorance and ask for help.
This must be in the FAQ, but I couldn't find it.

For exim 3.22 what is the minimal configuration tile, when running on

somemachine.school.edu

that will cause all mail sent to that machine, as

user@???

to be forwarded (relayed?) to

user@???

Exim is already running properly on the machine which will receive the
mail.

Thanks,

David Mathog
mathog@???
Manager, Sequence Snalysis Facility, Biology Division, Caltech