I am just completing a major Exchange 2003 to Exchange 2007 migration. All mailboxes and services have just completed migrating. Exchange 2003 decom is now required – after remedial action is taken with Recipient Update Policies and Public Folders.
Watch out for the move mailbox operation from Exchange 2003 to Exchange 2007 in the same Org. The Recipient Update Policy is enforced as part of the move – Microsoft feature !! This is not expected and can cause a lot of pain. You have to run an EMS command prior to the mailbox move to disable the checkbox that includes the mailboxes in Recipient Update. You can then move the mailboxes.
