[Exim] Smart Host?

In Sendmail, there is an option for what is called a SMART HOST. That would
be a host that handles all the outboud relaying of mail for a network
containing multiple mail servers. This is a handy feature for folks like me
who are on a dialup because that way we don't get blocked by the MAPS DUL
list. We can just send the messages to our ISP's mail server and let them
get sent from there. But I cannot figure out how to set this in Exim. Right
now exim is making the connections to the various servers directly, and it
seems to be working ok, but I want to know how to define that so that if we
start getting hit by the DUL we can get it fixed.

Thanks
Dan