When I migrate customers to Exchange Online I always recommend they maintain an Exchange hybrid server. There are several reasons for this recommendation; it’s much easier to manage SMTP addresses with an Exchange server on-premises, and it’s much easier to get your mailboxes back out of Office 365 if you maintain a hybrid server. To me, one of the great advantages of Office 365 is that I have never felt Microsoft was trying to “trap” customers in the service. They have always made it fairly easy to move mailboxes in and out of Office 365.

Of course when Microsoft makes unannounced changes to the way off boarding works, this is a little harder to sell.

As of sometime in December, you can no longer off board mailboxes from Exchange Online directly to an Exchange 2007 server. Try as I might, I am unable to find this documented anywhere in TechNet, but none the less attempting to migrate a mailbox from Exchange Online to an Exchange 2007 server will result in the error message

Unsupported target database version. The New-MoveRequest cmdlet can only move mailboxes to databases mounted on servers running one of the following versions of Exchange: Exchange 2013 and later versions, Exchange 2010 (SP2 and later versions).

To be fair, it was already a requirement that you have an Exchange 2010 (SP2 or better) or Exchange 2013 server setup as your hybrid server. You can still migrate your mailbox from Exchange Online directly to the hybrid server, and then do a mailbox move from the hybrid server to the Exchange 2007 server.

The problem with this work-around, as I see it, is that some customers may have hybrid servers that are not licensed to allow a mailbox to be move to them. Microsoft will allow customers to use a hybrid server for free, but that server is not licensed to host any mailboxes. Is this work-around technically breaking your license agreement with Microsoft? I’m not really sure, but it seems so to me.

In the real world, I don’t think the licensing concern is going to be a big deal for anyone. I’m pretty sure the licensing cops are not going to bust down your door if you off board a mailbox to your hybrid server for a couple of hours before moving it back to a properly licensed server.

The bigger concern for me is that this change seems to be completely undocumented. Doesn’t Microsoft have some level of responsibility to their customers to tell us about this sort of thing?