Can Groupwise Migrator for Exchange migrate to Exchange 2010 when it is installed on Windows Server 2012?
As of Groupwise Migrator for Exchange 4.2.x migration to Exchange 2010 or 2013 on Windows Server 2012 is supported.
Please see QStartGuide.pdf and the GME Release Notes.html in the documentation secion of the current install for the most up to date and detailed information.