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T-9 months: Exchange Server 2016 and Exchange Server 2019 End of Support

Platinum Contributor

Jan 15, 2025

On October 14, 2025, 9 months from today, Exchange Server 2016 and Exchange Server 2019 reach end of support. After October 14, 2025, Microsoft will no longer provide technical support for problems that may occur with Exchange 2016 or Exchange 2019 including:

Technical support for problems that may occur.
Bug fixes for issues that are discovered and that may impact the stability and usability of the server.
Security fixes for vulnerabilities that are discovered and that may make the server vulnerable to security breaches; and
Time zone updates.

Customer installations of Exchange 2016 and Exchange 2019 will of course continue to run after October 14, 2025; however, due to the upcoming end of support date and potential future security risks, we strongly recommend customers act now.

Our recommendation is for customers to migrate to Exchange Online or prepare their organizations to upgrade to Exchange Server Subscription Edition (SE) when it becomes available in early H2 of CY2025.

Migrate to Exchange Online or Microsoft 365

We strongly believe that you get the best value and user experience by migrating fully to Exchange Online or Microsoft 365. Migrating to the cloud is the best and simplest option to help you retire your Exchange Server deployment. When you migrate to the Microsoft cloud, you make a single hop away from an on-premises deployment, and benefit from new features and technologies, including advanced generative AI technologies that are available in the cloud but not on-premises.

If you're migrating to the cloud, you might be eligible to use our Microsoft FastTrack service. FastTrack shares best practices and provides tools and resources to make your migration to as seamless as possible. Best of all, you'll have a support engineer helping you from planning and designing to migrating your last mailbox. For more information about FastTrack, see Microsoft FastTrack.

Prepare to upgrade to Exchange Server SE

In May 2024, we provided an update to the Exchange Server roadmap, and details on how upgrade to Exchange Server SE if you intend to continue to run Exchange Server on-premises.

If you are running Exchange 2019, we recommend that you keep your Exchange servers up-to-date and you can upgrade in-place to Exchange Server SE when available.

If you are running Exchange 2016, we recommend that you perform a legacy upgrade to Exchange 2019 now and then perform an in-place upgrade to Exchange Server SE when available. You do have the option of a legacy upgrade from Exchange 2016 to Exchange Server SE RTM, skipping Exchange 2019 completely. But since there are less than 4 months between the release of Exchange Server SE and the end of support for Exchange 2016, that might not be enough time, depending on the size of your deployment and other factors (in-place upgrade from Exchange 2016 to Exchange SE will not be available). This is why we recommend that you upgrade to Exchange Server 2019 now, decommission your Exchange 2016 servers, and do an in-place upgrade to Exchange Server SE when it is available.

Note If you still have Exchange Server 2013 or earlier in your organization, you must first remove it before you can install Exchange Server 2019 CU15 or upgrade to Exchange Server SE.

Exchange Server Technology Adoption Program

If your organization intends to continue running Exchange Server and you want to test and evaluate pre-release builds of Exchange Server SE releases, you can apply to join the Exchange Server Technology Adoption Program (TAP).

Joining the Exchange Server TAP has several advantages, such as the ability to provide input and feedback on future updates, develop a close relationship with the Exchange Server engineering team, receive pre-release information about Exchange Server, and more. TAP members also get support at no additional charge from Microsoft for issues related to the TAP.

All nominations are reviewed and screened prior to acceptance. No customers are allowed access to any prerelease downloads or information until all legal paperwork is properly executed. Nomination does not mean acceptance, as not all nominees will be chosen for the TAP. If you are preliminarily accepted, we will contact you to get the required paperwork started.

Please note that even if you do not join the TAP program, you will still be able to test the code equivalent of Exchange SE in your organizations by installing Exchange 2019 CU15.

Related Microsoft Products Reaching End of Support on October 14, 2025

In addition to Exchange Server 2016 and Exchange Server 2019, several other products (some of which are often used with Exchange Server) also reach end of support or retirement on October 14, 2025, including Microsoft Office 2016, Microsoft Office 2019, Outlook 2016, Outlook 2019, Skype for Business 2016, Skype for Business 2019, Skype for Business Server 2015, Skype for Business Server 2019, Windows 10, and more.

You can search product and services lifecycle information to get detailed information for your Microsoft products and services.

Exchange Server Engineering Team

Updated Jan 23, 2025

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29 Comments

Ken Brussel
Brass Contributor
Jan 28, 2025
In-place upgrades are suggested for Exchange (considering CU15/SE is just another CU). You're also mentioning / reminding that Windows Server 2016 goes EoS in October. One thing that's not *quite accurate is that Windows Server 2019 (which we have Exchange 2019 deployed on today) leaves support completely in January 2029... so we have a little more time with the base OS.
What would be appreciated is having an in-place OS upgrade be a supported situation, this way we could upgrade to Server 2022 (and beyond) without having to remove and reinstall Exchange.
Rob_R
Brass Contributor
Jan 27, 2025
I've read this article, the "roadmap" article, and the "upgrading" article multiple times and I want to make sure that I understand what I've read:
1. Historically, extended support has included security patches; however, this is no longer the case. As of October 14, 2025 - MS will only provide case-based tech support to legacy Exchange after this date. Is this correct? (In my company, this means that the software either needs to be upgraded or removed)
2. If I recall correctly, when an Exchange server is Hybrid, CU/HUs must be installed 30 after their release to be supported by MS. So...if the RTM version of SE is released in August, this means that existing hybrid servers must be upgraded by September. Then when the HU is released "in late 2025", we have 30 days to upgrade - which also blocks co-existence with previous version. Because all of my on-prem servers are hybrid, they all have to be decommissioned by that time (or sooner because of no new security patches).
3. For those of us who are running E2019 on its original hardware & have been planning on the extended support period to work the upgrade process as we have with every previous version of Exchange (budgeting, building, jet stress testing, migration, etc.) we will have ~3 months to install, migrate, and decommission existing servers by the October 14th date because there is no way that my security leadership will allow an application to exist on the network where the vendor isn't maintaining its security. I'm curious if others have concluded that this will be their timeline as well.
- Nino_Bilic
  Microsoft
  Jan 27, 2025
  1. Exchange 2016 has been in Extended support since October 13, 2020 and Exchange 2019 has been in Extended Support since January 9, 2024. In other words – there was no change in extended support; both Exchange 2016 and 2019 have been getting security updates since they entered Extended support.
  
  2. This is essentially correct, yes. Note that the “running the latest CU” in hybrid applies to the server that is used as a hybrid endpoint in your organization. Not all servers in your organization are “hybrid servers”. Indeed, they are all running in hybrid mode, but they do not all automatically fall under the “should only run the latest CU” for support. But you are correct, that once Exchange SE CU1 is released, that (as currently planned) coexistence with older versions would be removed.
  
  3. As mentioned before, Exchange 2019 has been in Extended support for a year now. That support will end in October 2025. We have been asking our customers to, if they need to install new hardware, install Exchange 2019 on new hardware as we are enabling an upgrade from Exchange 2019 to Exchange Server SE RTM as a “Cumulative Update” upgrade. In other words. All that you’ll need to do is install a new Exchange 2019 CU (let’s call it “CU16” even though it will be called “Exchange Server SE RTM”). Exchange SE RTM will have no new features when compared to Exchange 2019 CU15, but it will switch you to a ”supported” path.
Richard-Artes
Copper Contributor
Jan 23, 2025
"Earlier this year" should read "May 2024" in my opinon. This article was published in Jan 2025.
- Nino_Bilic
  Microsoft
  Jan 23, 2025
  Thanks, fixed.
Sam_T
Iron Contributor
Jan 18, 2025
The_Exchange_Team
No CU15 as of January 2025 so Microsoft has missed an entire 6-month "H2 2024" release window. This and other problems have been going on for a long time:
1) Late releases for no good reason but just endless excuses like "threat actors", or "we heard that people have change freezes in December" or <insert excuse to fit the situation>.
2) CUs and HUs that obviously do not undergo any meaningful testing because customers are immediately exposed to the most basic of failures of the CU/HU that should have been picked up in Microsoft testing. Customers are left to suffer and bear the brunt and potential cost of resolution in relation to loss of business or support overtime.
3) Non-stop errors and omissions in EHLO blog posts that require seeming endless updates/clarifications/corrections to the original article which in turn means the articles can’t be trusted and you must spend hours wading through article updates and the comment section in each post to sort it all out.
4) Mediocre to poorly written documentation. Information is disjoint and spread out over blog articles and across modern "docs" webpages which are a poor substitute for what used to be better written articles in "TechNet". Things just seem to get worse at Microsoft.

The credibility of the Exchange team continues to approach zero. There is no reason to believe any target release dates provided by the team so there is no reason to believe any of the information or timeframes around "H2 2024" or Exchange SE or any other release dates.
As I have mentioned and others have mentioned previously, out here in the real world, people need time to plan, prepare and in some cases budget for application upgrades. Could be weeks, months, or a year+ for larger shops - Exchange is not the only application that people use believe it or not and there are few support people that have the luxury of being dedicated to Exchange in the real world. Everything comes down to time, priorities and $$$. It’s obvious to me that this team have little to no experience in a real-world Exchange on-prem environment and if any of you do it was probably many, many years ago. Your internal fantasy-land production or lab environments don’t count either.
Is really the best that a company with a 3+ trillion-dollar market cap can do ?   Why do you continue to have such blatant disrespect for your customer base and more specifically, people that support Exchange ?
- Marc__K
  Brass Contributor
  Jan 31, 2025
  Read the post again. The primary goal is to sell you Exchange Online. Under-funding and under-staffing the on premise product are ways to move toward that goal by worsening the experience so you want to go Exchange Online where everything is roses. We're lucky that there's even going to be an Exchange Server in 2026. It's clear that Oct 14 2025 was meant to be the death of the on-premise products and someone got talked down from that standoff. Why else would Exchange 2016 and Exchange 2019 have the exact same end of support date?
  - Sam_T
    Iron Contributor
    Jan 31, 2025
    Marc__K "The primary goal is to sell you Exchange Online" Hi Marc_K, I think many of us have had that feeling for a long time. However, it's still not a good reason for a company with a 3+ trillion-dollar market cap to abuse their on-premises customers which is what this has degenerated to.
- null-null
  Brass Contributor
  Jan 22, 2025
  I could not have agreed more.
  and the idea that somehow Seasoned Exchange admins are going to do in-place upgrade is beyond madness. Who does that???
  On one hand, MS does not support in place upgrade of the of the underlying OS that the Exchange server is running on, but then they tell you, oh yeah go ahead and do Exchange in place upgrade, mocking with thousand of files, what a recipe for disaster, Sam_T is absolutely right, there is no one left at Exchange group that is actually passionate about the product, really sad to see this ...
  - Marc__K
    Brass Contributor
    Feb 15, 2025
    I think it's been shown that in-place upgrades can work. Each Windows 10 feature update was essentially an in-place upgrade. And the Exchange CUs were really in-place upgrades. If the product team puts effort toward it, they can make it work. Seasoned Exchange admins got used to have to build new machines for new versions because the Exchange Team didn't want to put in the work to make in-place upgrades work. If they get around to supporting in-place upgrade of the underlying OS, that'll be the panacea. The past argument for doing a rebuild was "it's a new version, you need new hardware anyway". But if Exchange is in a VM, you can move it to new hardware very easily without reinstalling everything. Let the in-place upgrade method become the standard. But...Exchange Team you need to support upgrade of the underlying OS.
- Lothar_Lindinger
  Brass Contributor
  Jan 22, 2025
  You're telling exactly what needs to be said. Microsofts credibility regarding Exchange OnPrem currently is just beyond embarassing.
mguerra812000
Copper Contributor
Jan 17, 2025
I'm Just waiting for CU15 to be released so I can run server 2025. servers are built just waiting now
KeithPawson
Copper Contributor
Jan 16, 2025
The only reason we still have E2016 running is due to recipient management, all mailboxes and public folders are online. We struggle with this guide https://learn.microsoft.com/en-us/exchange/manage-hybrid-exchange-recipients-with-management-tools to be honest. While I've managed to create a new user from a workstation with Powershell, shutting down the exchange server prevents this and updating or modifying an existing users email/alias etc is not straight forward. Is there any better guide or tutorial on doing this? We would love to shutdown E2016 permanently, as it's going to be sometime before we can move 100% into Entra ID etc.
- Nino_Bilic
  Microsoft
  Jan 16, 2025
  Note that the article you referred to works ONLY if you have Exchange 2019 management tools installed. This will NOT work with Exchange 2016 management tools. In other words - you will have to extend the schema and prepare AD for Exchange 2019 (today, the newest version is Exchange 2019 CU14) and then install "management tools" on let's say a Windows workstation. There are a few more steps needed as per this bookmark in the article: Manage recipients in Exchange Server 2019 Hybrid environments | Microsoft Learn
  
  Once this is installed, the step 4 there will start the configuration of how to run PS from that workstation so it DOES NOT use the Exchange server you have installed currently. You will need to go through all of those steps, including on how to launch that PowerShell session on that workstation. That eventually gets you to Step 8 - which is where you should be able to create / manage objects even if you turned the Exchange 2016 server off (as a temporary test). Only after this works would you consider running the script mentioned later in the document to remove (not uninstall!) the last E2016 server.
  - Bhavesh Shah
    Copper Contributor
    Apr 08, 2025
    Nino, We are also in same boat. we have one E2k16 server only to manage recipient. If I understand correctly, I just have to extend schema and prepare AD for Exchange 2019 CU15. After this we don't have to install full E2k19 but just Managment tools of E2k19 CU15. Then gracefully shutdown E2k16 server with out uninstalling server.
    
    Will this allow us to in place upgrade to Exchange Server Subscription Edition when it is released?
    
    I just want to make sure if we will be allowed to inplace upgrade to Exchange Server SE whenever it is available.
KeithPawson
Copper Contributor
Jan 16, 2025
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maltebruenger
Copper Contributor
Jan 16, 2025
I find this post a bit cheeky, considering that Exchange Server 2019 CU15 has still not been released. I would love to prepare the environment for Exchange Server SE, but for that I would need CU15.
The linked article (https://techcommunity.microsoft.com/blog/exchange/upgrading-your-organization-from-current-versions-to-exchange-server-se/4241305) still refers to H2 CY 2024. There was still no release for this week's patchday.
What is the status? When can we expect Exchange Server 2019 CU?
- Nino_Bilic
  Microsoft
  Jan 16, 2025
  CU15 is coming "soon". I am sorry, I know this does not answer what you are asking, but it is true. There is no "date" that we have planned and are waiting for to arrive, rather, we will release when we are ready to release. CU15 being an RTM equivalent for Exchange Server SE, we want to be able to make good on the promise of not making changes in SE RTM (other than security update payload between CU15 and SE RTM release).
  
  BTW, we (Exchange team) never release CUs on Patch Tuesday; this is a "security update day" really, and we would traditionally release CUs a week after (but that is just a soft target, we can release a CU any day we have it ready to release, except we specifically try to avoid Patch Tuesday). SUs we would release on Patch Tuesday.
  
  I just updated that post also, thanks for pointing that out. Truth is - the through to update this before has crossed my mind but then I forgot to do it. :(
  - AWeinmann
    Copper Contributor
    Jan 22, 2025
    Cu15 had two dates where it was scheduled to arrive: H2/2024 and January 2025.
    Is the October 2025 date for Exchange SE set in stone or may the release also be moved to 2026?
stefandechert
Brass Contributor
Jan 15, 2025
Hi The_Exchange_Team
seems like the TAP has a prerequisite "testing in productive environments".
We are very interested in participating the program, but using pre-release builds in productive environments is a show stopper for us.
Is it possible to apply for the program only testing in our dev/staging-environments?
- Nino_Bilic
  Microsoft
  Jan 15, 2025
  Note that the requirement for TAP is not "convert / upgrade all of your production environment to pre-released version" but we expect our TAP participants to run in production, yes. There might be several "rings" of release so for example we might provide a very early version and suggest "lab only" and then provide a later build and say, "production ready".
  
  But the point is to get "real world" exposure to new code / builds and this is simply not possible in lab / dev environments.
  
  If your organization does run a sizable staging / dev environment with real-life (production) workload, then it might make sense. You can apply and we can evaluate the application. But usually staging / dev environments do not provide things like substantial volume of email, number of clients connecting etc. to really see how new changes impact production environments, but yours might be different...