[Exim] Alias one domain to another

Hi, hope someone can help me.

I'm trying to sort out how to alias an entire domain onto another domain
with Exim, so that any addresses added to domain1 are automatically aliased
to domain2. Right now, the only way seems to manually alias individual
email address, and as we have several hundred accounts with one to four
domains to alias on to each, this is a real pain.

We were able to do this in the past quite easily on EIMS on mac, so I'm
hopeing Exim 4.20 has the same capability.

Thank you,

Laura Proseilo