2003 to 2016 DFL/FFL

Question

I am in charge of 3 forests that are all configured in all joined into a forest trust. two of the domains are 2003 dfl/ffl while 1 is 2008 r2. I have exchange 2007 in place. I am looking to upgrade the DFL/FFL of the lower level domains before raising the 2008r2 domain dfl/ffl then to Windows 2016. In devising my strategy I am trying to determine if I can go straight from windows 2003 to windows 2016 DFL/FFL or must I go to 2008 r2 first. I am aware that I have to migrate FRS to DFS-R as part of this process. Also, does exchange 2007/2010 support DFL/FFL 2016?

Answer 1

Yes, basically. Above is per domain. One domain doesn't affect the other in respect to this.
https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/active-directory-functional-levels

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Answer 2

Exchange 2010 SP3 RU20 and later RU versions support Windows Server 2016 Domain Controllers and Windows server 2016 forest function level.
Exchange 2007/2010 has been ended of support, those KB articles are not available in official sites, these previous articles should help:
https://blog.rmilne.ca/2018/06/19/exchange-2010-sp3-ru22-released/
https://blog.rmilne.ca/2018/06/21/exchange-2010-support-for-windows-server-2016-domain-controllers/
And we suggest to migrate to Exchange 2016/2019/Online for better using experience, follow the assistant to plan your migration: https://assistants.microsoft.com/
If you need further assistance about Exchange, please start a new thread with Exchange tag.
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