[Exim] different SSL certs for different IPs?

Sorry for the barrage of questions this week...

I want to provide SSL-based SMTP and IMAP for two domains. People will
be connecting to "mail.foo.com" and "mail.bar.com" (each of which has
its own IP).

For the SMTP side - is there a way to get exim to present a different
cert depending on what IP the connection came in on? Or do I have to run
two parallel processes (and if so, could someone share any
configuration hints?)

If anyone happens to know the (courier-) IMAP side of this, I'd love
an answer to that too...


--
Daniel Drucker / dmd@???