[EXIM] Failover Hosts

Hello all.....
I am trying to set exim up to have a automatic failover if it sees that the system
that it is sending all mail to is down. The exim box is the gateway that passes
to a Notes server. If the notes server goes down, I want to point exim to a
different server, can exim do this automatically? I have looked over the docs,
and haven't seen anything with this.
Thanks for the help,
Paul Yahnig