Update 6/13/2025: Please see our new blog post for updated timelines of releases as well as additional details on how to get from current versions of Exchange Server to Exchange Server SE: Upgrading ...
Updated Jun 13, 2025
Version 14.0
Blog Post
In an Exchange 2019 environment running on Windows Server 2019, is an in-place upgrade from Exchange 2019 to Exchange Server SE supported? or do we need to upgrade the environment to Windows Server 2022 or 2025?
It will run on Server 2019. It is recommended to upgrade to newer server OS for longer term support of the underlying OS.
Would anyone upgrade 2019 to 2025 with Exchange on it, or do a swing upgrade as before? As in: upgrade the OS and then upgrade Exchange to SE?
The current suggestion to install Exchange on Windows 2025 is for the very reason that once the underlying OS becomes end-of-life (October 9, 2029 for Windows 2025, OR, October 10, 2034 for extended support), you will need to perform another (still non-trivial) traditional Exchange migration. Doing the necessary work on a Windows 2025 system extends the support until those dates and pushes out your deadline to perform your next Exchange OS Migration. Currently, Windows 2019 is EOL (for mainstream support) and is in extended support until January 9, 2029.
I believe the question comes down to...
- Do you want to migrate Exchange to a new OS now, while you may be migrating Exchange in preparation for SE anyway, which for Windows 2025 would push your next required migration out until 2034 (at the latest, unless support for underlying OS upgrades changes)
- OR - - Do you want to save some time now, wait and not upgrade the OS now, and be forced to by 2029?
As has been said numerous times and has been the case forever(?), unfortunately, the OS on which Exchange is running cannot be upgraded while Exchange is on it. Microsoft is aware of the myriad requests to support this and has indicated they are investigating. After SE is released; the underlying OS upgrades will become the primary driver for Exchange Migrations (no-longer Exchange version changes... assumes SE is the "last" version).
Ultimately, if you're running Windows 2019, 2022, (or 2025) now, you don't need to upgrade the OS, but you will need to upgrade sooner than if you were to upgrade to 2022 or 2025 now.
In our real-world scenario, since we had to perform a traditional Exchange 2016 to 2019 migration anyway (due to 2016 AND 2019 final EOL this October, and 2019 being the only in-place upgrade path to SE), I upgraded to Windows 2022 at the same time (this was prior to Windows 2025's release). This means I'll have until October 14, 2031, at the latest, to upgrade the underlying OS. Had I waited for Windows 2025's release migrated to Exchange 2019 on Windows 2025, I would have been able to upgrade the underlying OS as late as October 20, 2034, three years later).
Overall, this is good news IMO. What used to require two separate upgrades/migrations, a.) the underlying OS when necessary and b.) major version changes of Exchange when necessary; now seems like it might only require one, the underlying OS when necessary, given Exchange SE should (grain of salt) be the last version of Exchange ever (of course, perpetually evolving with CU's, SU's, and HU's).
That's my short story, long...
- Do you want to migrate Exchange to a new OS now, while you may be migrating Exchange in preparation for SE anyway, which for Windows 2025 would push your next required migration out until 2034 (at the latest, unless support for underlying OS upgrades changes)
