http://www.devarticles.com/art/1/309
this article talks about using SENDMAIL() with the exhcnage server....easy to do and most mail programs support this method
also
see the [man]COM[/man] section in the manual
to create a new COM object for mail use
$objMail = new COM("CDONTS.NewMail")
you will have to play around to see about using this for html emails and other functions...
hth