With the release of Exchange Server 2016 CU3, Microsoft has announced the support for running Exchange Server with Windows Server 2016. Note that these announcements are for general availability of Windows Server 2016 (expected to be announced at Ignite 2016), not for any pre-release/technical preview builds.
Update: an update is required for Windows Server 2016 to resolve underlying issues that adversely impact Exchange 2016 servers.
Outlined in Microsoft's release blog post are the following requirements:
- Exchange Server 2016 CU3 or later is required for Windows Server 2016 support.
- Windows Server 2016 domain controllers are supported, as long as the Forest Functional Level is Windows Server 2008 R2. Exchange 2016 and all other currently supported versions (2007-2016) will work with FFL of 2008, so you'll need to increase the FFL to 2008 R2 if you plan to use WS2016 domain controllers.
- Windows Defender is included with Windows Server 2016 and enabled by default, therefore the appropriate file and process exclusions must be added (currently these are quite complex but there's a possibility of a much simpler set of exclusions being used in future).
Included in Microsoft's announcement is the news that Exchange Server 2013 will not be supported on Windows Server 2016. It's normal for older Exchange releases to not be supported on operating systems that are released years later, so this is not a big surprise.
The Exchange Supportability Matrix has been updated with information about Windows Server 2016.
Update: the supportability matrix has been updated to clarify the different support for Exchange 2016 CU2 and earlier vs 2016 CU3 and later.
As I'm writing this there's some details in the matrix that don't quite line up with the advice in Microsoft's blog post. The matrix indicates that Windows Server 2016 domain controllers are supported for use with all currently supported versions of Exchange (2007-2016), while the blog post states that Exchange 2016 CU3 or later is required. I suspect this is just an issue with the wording of the announcement, and that CU3 is only required when installing Exchange 2016 *on* a WS2016 server. The support matrix is probably correct, but I'm hoping for a clarification on that point. The matrix also indicates that Windows Server 2008 (not 2008 R2) FFL is supported (which it is) but doesn't call out the specific requirement to upgrade the FFL to a minimum of 2008 R2 when using WS2016 domain controllers with Exchange 2016. Of course, those could just be issues with my interpretation of the announcement, but I find it best to call out such things so that customers don't stumble into unsupported scenarios by accident (as we've often seen in the past).