Google Apps Technical Transition Guide For Business, Education, and Government - Manual (Page 33)

Mail Data Migration 33
You should migrate shared contact information for any users and distribution lists that
you aren’t fully activating in Google Apps during this phase. Doing so allows your
early adopters to see the shared contact information for all users and distribution lists
from within Google Apps.
Note: During the Global Go Live phase, you’ll migrate your distribution lists as
Google Groups; for now, you’ll simply migrate their shared contact information.
• Consult the documentation for the email migration tool you selected during the
Core IT phase for more information on migrating shared contacts.
Global Go Live
Finish migrating user mail data
Level of Effort: Moderate to High (depending on tool used)
During this phase, you’ll migrate all mail data you didn’t migrate during the Early
Adopters phase. Continue to use the same mail migration tool that you’ve used up to
this point.