Exchange 2019 Migration

For Exchange 2019 read below comments.

Windows Server 2012 R2 is the minimum OS and AD for Exchange 2019, if Exchange RTMs before October 2018 when Windows 2012 R2 goes into extended support. If Exchange 2019 RTMs later, we may see the minimum requirements set to Windows Server 2016 instead.

For Windows domain 2012 R2 inplace upgrade to windows-server-2019 read below comments.

http://louistechviews.com/2018/04/10/in-place-upgrade-windows-server-2012-r2-to-windows-server-2019-preview-maybe/

For Windows domain controllers on 2016 inplace upgrade to windows-server-2019 read below comments.

https://www.starwindsoftware.com/blog/in-place-upgrade-domain-controllers-from-windows-server-2016-to-windows-server-2019

So since minimum requirement for OS and AD for exchange 2019 is Windows Server 2012 R2 and you are on Windows Server 2012. I would say you will have to migrate your AD to the new Windows Server 2012 R2 first, then move all FSMO roles and feature from old existing AD and then you need to demote your 2012 domain controllers. So once you are on supported platform then you can install a new OS(Windows Server 2012 R2) on a new VM for exchange and then install exchange.

windows 2012 R2 AD is supported by Exchange 2019 , Outlook client support will be 2013 and later... any how still there is no exact prerequisites and upgrade compatibility untill they release the Exchange 2019 RTM.

better wait and watch untill release and stable the application

all the best

My domain is already Window 2016. For the new Exchange server 2019, I will install it on a Window 2019 server as well.

Hence, I don't need to explicitly buy Window 2019 client CALs - saving some money for the migration, correct ?

Thx