Exchange 2010 SP3 prepares the way for Exchange 2013

Given the fuss around the Microsoft Exchange Conference, you might have missed Microsoft's announcement of the upcoming release of Exchange 2010 Service Pack 3, but I didn't. Indeed, it was a strange announcement in some respects because Microsoft generally doesn't announce a service pack some three or four months before the software shifts. In this case, they had to release the news (which was an open secret anyway) because sessions at MEC such as "co-existence with Exchange 2013" discussed the need for customers to deploy Exchange 2010 SP3 before they can install Exchange 2013.

A host of architectural and other changes are in Exchange 2013, many of which flow from the decision to retrench Exchange server roles into Client Access Server (CAS, or front-end) and Mailbox (or back-end). The older Hub Transport and Unified Messaging roles have been succumbed into CAS or Mailbox and there's been a redistribution of workload across the server roles to make the CAS a true stateless server.

Older servers have no knowledge of the changes in Exchange 2013. It's logical that these servers would need to be updated to be able to co-exist alongside Exchange 2013 in the same organization. Exchange 2010 SP3 updates servers so that they can exchange messages and proxy connections with Exchange 2013 – and share the upgraded Active Directory schema required by Exchange 2013 to support its range of new features such as Data Leak Protection. You'll need to apply SP3 to all Exchange 2010 servers known to your organization, including Edge servers. If you don't, the Exchange 2013 setup program won't work because it'll detect servers running an unsupported version and refuse to go further.

Another potential benefit gained from Exchange 2010 SP3 is its support for Windows 2012. This won't make any different for existing servers as you can't upgrade the operating system on a server that has Exchange installed on it. But it does mean that you could decide that Windows 2012 is the preferred long-term platform for Exchange 2010 and Exchange 2013 and embark on a program to introduce new Exchange 2010 SP3 servers running on Windows 2012 to replace older Exchange servers running on Windows 2008 R2 (or Windows 2008 SP2) in a rolling upgrade.

You'll also need to upgrade Exchange 2007 servers before they can co-exist alongside Exchange 2013. Microsoft hasn't announced yet what update will be required but it's likely to be something like a roll-up update for Exchange 2007 SP3. Given that Exchange 2007 SP3 RU8 is the current release, the required version might be RU9 – or maybe RU8 will suffice. Microsoft will reveal all in their own good time.