Exchange updates improve ActiveSync client migrations

Mobile devices are a pain point during a mail migration to Office 365, but a new Exchange Server feature promises to fix that.

Although more organizations have started using mobile device management options, the majority of IT teams moving to Office 365 have to go through the pain of manually reconfiguring smartphones and tablets.

Exchange Server 2013 Cumulative Update 8 (CU8) and Exchange Server 2010 Service Pack 3 Rollup Update 9 (RU9) introduce a feature that, given the right set of circumstances, can make the switch happen automatically.

In theory, most ActiveSync clients can automatically reconfigure themselves to use Office 365. On the server-side, Exchange had never received an update to allow this to happen. Although it isn’t supported by all clients, Exchange ActiveSync includes the ability to send the HTTP status code 451, which means the device is misconfigured. From Exchange 2007 onward, this let a server redirect ActiveSync clients to a better, more appropriate Client Access Server within the organization.

In an on-premises Exchange implementation, this allowed the ActiveSync client to update settings as mailboxes moved. For example, if employees relocated from the U.K. to the U.S., their mailboxes would often be moved. Their ActiveSync client would most likely connect via the U.K. however, so this feature gave the ActiveSync client an opportunity to update its settings.

A move to Office 365 in a hybrid Exchange environment isn’t quite the same. When a mailbox moves from on-premises Exchange Server to Exchange Online, the change is similar to a cross-forest mailbox move — those accounts may mirror your on-premises Active Directory (AD), but they’re in Microsoft’s own AD forests.

As a result, there was no technical mechanism built into Exchange to use its knowledge that the hybrid relationship was in place or to provide a similar redirection message to clients — until now. Exchange 2010 SP3 RU9 and Exchange 2013 CU8 now include a feature that redirects the ActiveSync client to Office 365 after the mailbox migrates to Exchange Online.

Read more about how the ActiveSync updates work, and how to get ready in advance, over on SearchExchange…