Shaitand
First, what does Exchange have to do with audio?
Secondly, what are you looking for? A replacement for the Exchange Server? Sorry, probably not happening. If you HAVE a need for Exchange, you buy Exchange, right?
But, you mentioned "business desktop". Why not go with Evolution, then? Talks with Exchange, does mail, calendar, notes and contacts. What more would you need? The only thing "missing" is the ability to change your Windows Domain Password. So, just use an RDP client (Remmina would be one choice) to log in to a Windows Server in that Domain. For instance, try to log in to the Exchange Server. Of course you (probably) because you would have to be an administrator, but the ATTEMPT will allow you to update your password.
Mail - check
Notes - check
Calendar - check
Contacts - check
Password Change - check
RDP - check
Now, Evolution is (in my opinion), far better than the Windows Exchange client. Talks to more server types, allows a choice of spam control, better signatures, threads both Microsoft and Unix emails, and more.
So try it -- if it works for you, problem solved, right?
(I was forced to use Windows Exchange client a few years ago. I was shocked that emails weren't threaded! But, I think this has been sorted recently -- just not compatibly).