I have an install of Unity running perfectly with Exchange 2007. All of the exchange servers are running OS 2008 except for the partner server which is running OS 2003. We have recently built a new server with Exchange 2007 and OS 2008 (identical to the other ones). I ran permissions wizard and everything passed. When we move an account to this server everything works EXCEPT for the MWI light on the phone. If I go into the registry and delete the MAPI cache this new server will work perfectly for about 1 day and then go back to the light not working.
Any idea what could be causing the MAPI cache to corrupt only this one server connection?