We are currently running a Exchange 2007 SP1 production email environment. We do not have legacy features enabled (public folders) since we have Outlook 2007 clients across the board. In the Unity Install Guide, it mentions that 2007 legacy settings must be enabled for Unity to function properly.
What features will not work because legacy mode is not enabled? And is there a version of Unity 7 that has native Exchange 2007 support?
From my TAC exp, you need the OAB or else Unity won't deliver and forward messages properly.
It's a requirement that you need to enable the OAB per link.