So I upgraded to the latest 4.2 for my 3300, am using Exchange 2007 Unified Messaging as my voicemail and a 3rd party app from AaronSoftware called Exchange MWI Enterprise and I still can't get MWI to function. Exchange UM has been working fine for over a year, so obviously my network elements and SIP peers are working correctly. According to Mitel anything above 4.1 supports unsolicited sip notification and works with Exchange 2010 and according to the 3rd party developer, this application works exactly the same as exchange 2010.
When I run the test app from the 3rd party app I am getting the error "SIP/2.0 404 Not Found" and we are just not ready to migrate to exchange 2010....
