We are in the process of doing a staged migration from exchange 2003 to office 365. We have dirsync working and have migrated most of our mailboxes to office365. We have also converted all migrated mail boxes to mail enabled users that have been migrated. After we finish with migrating the last mailbox and convert it to a mail enabled use we would like to completely decommission our on-premises Exchange organization. We are not using a single sign-on solution and there is no federated server just dirsync. The Migrate Mailboxes to Exchange Online with a Staged Migrationhttp://technet.microsoft.com/en-us/library/jj874018(v=exchg.150).aspx says “Decommissioning Exchange can have unintended consequences. Before decommissioning your on-premises Exchange organization, we recommend that you contact Microsoft Support”. Well no one at Microsoft Support will talk to me because support for Exchange 2003 has ended.
The procedure for Uninstalling Exchange Server 2003http://technet.microsoft.com/en-us/library/bb125110(EXCHG.65).aspx says before you begin that you cannot uninstall Exchange Server 2003 from a server if it is the only server in your organization running the Recipient Update Service. Instead, you must first use Exchange System Manager to enable the Recipient Update Service on another server. Well this is the last exchange server so I have no place to move it to.
I need to know the correct procedure for Decommissioning the last exchange 2003 server after migrating to office 365.I also must avoid the “unintended consequences” that the Mailboxes to Exchange Online with a Staged Migration procedure warns about.