Domain Functional Level Required For Exchange 2016
All exchange 2010 role servers including edge transport should be sp3 ru11 or above.
Domain functional level required for exchange 2016. There is a nuance with the latter. Forest and domain functional level should be windows 2008 or later. Forest functional level should be windows 2008 or above.
So now at the time of exchange 2016 preview release the active directory requirement changed to the following but remember it is still under preview and requirement can change before the rtm release. For two cases you may receive error that the function level should be upgraded to windows server 2008 r2 or later. Exchange 2016 active directory forest functional levels one of the minimum requirements for exchange 2016 installation is active directory forest function level which should be 2008 or later.
All exchange 2013 role servers including edge transport should be cu10 or above. Exchange server 2016 active directory requirements are to install exchange server 2016 the ad ds forest functional level must be windows server 2008 read only domain controller are not supported on exchange server 2016 or any other versions. The confusion relates to our support of windows server 2016 with exchange server 2016.
The windows 2016 domain is the highest available dfl for active directory. Just one block one role exchange 2016 prerequisites supported forest functional level for exchange server 2016 active directory must be at windows server 2008 forest functionality mode or higher. Dcs can support automatic rolling of the ntlm and other password based secrets on a user account configured to require pki authentication.
The blog included a statement that read domain controllers running windows server 2016 are supported provided forest functional level is windows server 2008r2 or later. Only tap customers can install it in production. Read only global catalog servers and read only domain controllers are not supported.
Operating system environment exchange 2019 exchange 2016 cu12 and later exchange 2016 cu7 and later exchange 2016 cu3 to cu6 exchange 2016 cu2 and earlier exchange 2013 sp1 and later exchange 2010 sp3 ru22 or later exchange 2010 sp3 ru5 ru21. There is no windows 2019 domain level. Windows server 2016 domain functional level features all default active directory features all features from the windows server 2012r2 domain functional level plus the following features.