Updated 9/18/2014: As of this writing, Windows Server 2012 R2 domain controllers are supported against all supported Microsoft Exchange environments:
- Exchange Server 2013 with CU3 or later (remember, CU5 and CU6 are the two versions currently in support; SP1 is effectively CU4)
- Exchange Server 2010 with SP3 and RU5 or later
- Exchange Server 2007 with SP3 and RU13 or later
Take particular note that Exchange Server 2010 with SP2 (any rollup) and earlier are NOT supported with Windows Server 2012 R2 domain controllers.
Also note that if you want to enabled Windows Server 2012 R2 domain and forest functional level, you must have Exchange Server 2013 SP1 or later OR Exchange Server 2010 + SP3 + RU5 or later. Exchange Server 2013 CU3 and Exchange Server 2007 (any level) are not supported for these levels.
In the past couple of months since Windows Server 2012 R2 has dropped, a few of my customers have asked about rolling out new domain controllers on this version – in part because they’re using it for other services and they want to standardize their new build outs as much as they can.
My answer right now? Not yet.
Whenever I get a compatibility question like this, the first place I go is the Exchange Server Supportability Matrix on TechNet. Now, don’t let the relatively old “last update” time dismay you; the support matrix is generally only updated when major updates to Exchange (a service pack or new version) come out. (In case you haven’t noticed, Update Rollups don’t change the base compatibility requirements.)
Not that kind of matrix…
If we look on the matrix under the Supported Active Directory Environments heading, we’ll see that as of right now Windows Server 2012 R2 isn’t even on the list! So what does this tell us? The same thing I tell my kids instead of the crappy old “No means No” chestnut: only Yes means Yes. Unless the particular combination you’re looking for is listed, then the answer is that it’s not supported at this time.
I’ve confirmed this by talking to a few folks at Microsoft – at this time, the Exchange requirements and pre-requisites have not changed. Are they expected to? No official word, but I suspect if there is a change we’ll see it when Exchange 2013 SP1 is released; that seems a likely time given they’ve already told us that’s when we can install Exchange 2013 on Windows 2012 R2.
In the meantime, if you have Exchange, hold off from putting Windows 2012 R2 domain controllers in place. Will they work? Probably, but you’re talking about untested schema updates and an untested set of domain controllers against a very heavy consumer of Active Directory. I can’t think of any compelling reasons to rush this one.