On October 14, 2025, six months from now, Exchange Server 2016 and Exchange Server 2019 will reach end of support. It’s critical to plan your upgrade now to remain supported and secure.
After October 14, 2025, Microsoft will no longer provide technical support, meaning that Exchange 2016 and Exchange 2019 users will no longer receive:
- Bug fixes for issues that may impact the stability and usability of the server.
- Security fixes for vulnerabilities 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, continuing to use these offerings after the end-of-support date invites potential security risks, so we strongly recommend taking action 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 July 2025. One of the ways to make this transition easier is to install Exchange Server 2019 CU15 now. That makes it possible to in-place upgrade from Exchange 2019 to Exchange SE (when available), making the transition significantly faster and easier.
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 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 to 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 it becomes available later in 2025.
If you are running Exchange 2016, we recommend that you perform a legacy (a.k.a. side-by-side) upgrade to Exchange 2019 now and then perform an in-place upgrade to Exchange Server SE once it’s released. 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 only a few 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 from Microsoft at no additional charge for issues related to the TAP.
All nominations are reviewed and screened prior to acceptance. No customers are allowed access to any pre-release 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.
Exchange Server Engineering Team
