Migrate from Microsoft Outlook
Your users can migrate their own mail, contacts, and calendar data from Microsoft® Outlook to their Google Apps account, using Google Apps Migration for Microsoft Outlook (GAMMO). Users can step through an easy-to-use wizard to migrate data from either a Microsoft Exchange account or a local PST file. Or you can run GAMMO from the command line to migrate data on behalf of another user.
Ready to begin? See Administrator setup for GAMMO.