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).

About the Author

Paul Cunningham

Paul is a former Microsoft MVP for Office Apps and Services. He works as a consultant, writer, and trainer specializing in Office 365 and Exchange Server. Paul no longer writes for Practical365.com.


  1. Babar

    Hello Paul, i am using exchange 2016. some user mail box size increased up to 82 GB i am unable to delete mails from deleted items while i i am not using any exchange retention policy.

  2. Jude Siegfred

    Hi sir Paul,

    is windows server 2016 data center core edition or standard compatible for installation with exchange server 2013 standard?

  3. Uduak Ekaette

    Paul we currently run Exchage 2003 at HQ, we plan to make 7 Exchage 2019 sites, we want a well plan strategy for redundancy and high availability about 45 remote offices are to join please advice is needed.

  4. Michael

    hi Paul Cunningham, sorry if this is a bit off-topic, but we are currently running exchange 2013 with 2012 r2 AD . is it possible for 2013 exchange to run with 2016 DC’s ? Or we have to keep one 2012 r2 DC for it to work ?
    Or even better, what about 2019 DC ?
    We have already upgraded the schema to 2019 as we use 2019 ADFS.
    thank you for your time

  5. Lakshmi S

    Hi Paul,

    I want to create a static rule on the exchange server. Rule should identify the client (I.e. outlook/OWA etc) and based on the client it should send the mail to another person for moderation.

    Thanks in advance…

  6. Aajay

    Current Setup: DC-2008 ffl-2008
    Exchange 207sp3 Ru21.

    Can we upgrade my AD piece from 2008 to AD-2016 with ffl at 2008 and latter as we migrate to O365 upgrade to AD-2019 with latest ffl.

  7. Barry

    Hi Paul,

    I am a bit unclear on Exchange 2010 support with Server 2016 DCs. On investigation of the matrix, under the supported Active Directory Environments, the Operating System Environment table suggests using Exchange 2010 systems with 2016 DCs is unsupported, even if the OS on the Exch2010 servers is 2008R2 and forest functional level is still 2008R2. Is that how you would interpret it?

    If that is true, should we update any Exchange servers to Exch2016 first before updating the DCs to 2016?

    1. Barry

      Just to confirm, we are a multisite organisation with 5 Exchange sites and a number of other sites with DCs but no Exch servers. Our DCs are 2008R2, Exchange servers are 2010 SP3 latest rollup in hybrid configuration, and Forest Functional level is 2008R2.

    2. Avatar photo
      Paul Cunningham

      You need to have supported DCs in the sites where Exchange 2010 is deployed so that 2010 can talk to those DCs. You can deploy 2016 DCs as long as there are still supported DCs in the Exchange sites. The functional levels must be kept at one of the supported levels until all your 2010 servers are decommissioned

      All that said, you should plan to upgrade to Exchange 2016, in my opinion.

  8. Aviwe

    Hi Paul
    I just installed Server 2016 on VBox as a VM. Now is it possible to run exchange 2010 into Server 2016? If so, what are the prerequisites of installing it onto Server 2016?

      1. Peter

        I dont agree, we have Server 2016 running with Exchange 2010 SP3 without any problems. It might not be supported, but its working.

        1. Avatar photo
          Paul Cunningham

          Deliberately running an unsupported Exchange/OS combo?

          Good grief.

  9. Amjad

    Recently i have migrated from Exchange 2010 to Exchange 2016 CU4. After migrate i am getting 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain error even i configured Receive Connector and Send Connector. Still it is giving the same error. I followed according to this article https://www.practical365.com/exchange-server/exchange-2016-smtp-relay-connector/ also getting the same error. Could you please tell me how to solve this issue.

  10. Muhammad Usman

    I have recently installed exchange server 2016 on win 2016 servers. My environment is having i.e. abc.com domain/ dns with A.D. All is set up but when i try to send email from newly deployed exchange message stays in draft and says please try again later, we are still not ready. Can anyone support?


  11. Nav

    Paul ,Please let me know your thought on monitoring the exchange 2016 ,it becoming a challenge now.

    1. Avatar photo
      Paul Cunningham

      I think you should monitor it, yes. Is there something specific you’re asking?

  12. Nima

    Dear Paul, Thanks for yet another great article. I run an Exchange 2013 with Windows 2012R2 environment (exchange and domains). I have been waiting for Windows 2016 to migrate to Exchange 2016. Can I follow the process below as I have done with all previous versions?

    1 – add Win2016 DCs to the environemnt
    2 – remove win2012R2 DC
    3 – Add exchange 2016
    4 – migrate all
    5 – remove exch 2013

    Many thanks

      1. Nima

        Thank you very much, as always 🙂

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