MS Exchange server on FreeBSD?

[Christian Tischler]

As I follow this discussion an idea/question forms in my head.
The server side should be managed by BSD, but the client side is most 
surely an heterogeneous group.
So a solution to somehow emulate/simulate an exchange server on an box 
(or cluster of sql horde what ever servers), and import this e.g. 
calendar data into a BSD solution. As I understand the so far mentioned 
products, these are quite capable of doing so. Then there would be an 
easy solution to different likes in clients.
As I am not at all a skilled programmer I can not appraise the work that 
would be needed to establish such a thing.

Christian