I assume this would be a self defeating, pain in the neck, that would be liking to Fort Knox made out of swiss cheese. Exchange 2K on a FE/BE setup needs to be in the same forest so this would mean you'd have DMZ interlan communication. So you would be comprimising your internal ISA server, right?!? What about putting a relay in the DMZ? Would all this be worth it? What about IIS? Any thoughts I would appreciate especially on the combination configuration. Thanks
It depends on how you want to approach things. You certainly could put the FE in the private address DMZ, but then you've extended your internal network security zone into the DMZ, which might not be what you want to do.
An SMTP mail relay does fit nicely into a DMZ, because the realy doesn't need to be part of the internal network security zone.