The situation is as follows...

We have 4-5 sites hosted on an IIS box ( apps on the site require asp ), but our old free-bsd based mail server died.

I really love Cpanel and exim and would like to be able to host just email for these sites on our main cpanel box.

I have complete control over the DNS for all this, and can modify it any way necessary.

I hope someone can point me in the right direction here.