Here's the problem. I have quite a bit of latitude with my email server but I need to keep my Blackberry server and Avaya IP office running. As far as I know right now, these just authenticate with Active Directory for the Integrated Messaging Exchange Account so it can send voicemails to the user's mailboxes and the Blackberry just forwards mail onto the Blackberry user's Exchange accounts.
SO, why can't an open source mail server authenticate with these apps? Any ideas? I think that I will still have to run a Active Directory box for Blackberry.