ADModify is a tool that will enable an AD/Exchange admin to make bulk
changes in user properties.
One of the special treats of this tool is the fact that it provides a simple GUI for
configuring the accepted MAPI level for clients.
You can download the tool at:
http://www.gotdotnet.com/workspaces/workspace.aspx?id=f5cbbfa9-e46b-4a7a-8ed8-3e44523f32e2