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Reminder: Exchange 2016 and 2019 ESU Program Ends in October 2026

The_Exchange_Team's avatar
The_Exchange_Team
Platinum Contributor
Jul 20, 2026

Over the last several weeks we have received several questions about possible extension of the Exchange Server 2016/2019 ESU program past October 2026. After all, in our original Exchange 2016/2019 ESU announcement we said that there would be no extensions, but then we ended up creating a Period 2 Exchange ESU program that is scheduled to end with October 2026. We are just about at the mid-point of Period 2 Exchange ESU now.

There will be no further extension of Exchange 2016/2019 ESU program timeline. Once October 2026 ends, there will be no further updates for Exchange 2016/2019, even if you currently have a Period 2 ESU.

If your organization still uses Exchange 2016 or 2019 in production:

Please review Microsoft Exchange Online and Exchange Server Licensing FAQs especially "What is Exchange Server Subscription Edition (SE) and how is it licensed?” section. Exchange 2019 and Exchange SE licensing requirements are the same.

The Exchange Server Team

Updated Aug 14, 2026
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7 Comments

  • Kenneth650's avatar
    Kenneth650
    Copper Contributor
    Sep 30, 2026

    Hi Nino_Bilic​ ,

    I would like to verify that the Exchange Emergency Mitigation services on 2016 and 2019 versions will keep functioning for the time being for servers that had the last available ESU updates. I am under the assumption it will keeps working and receiving mitigations until a SU (or CU?) is needed similar like the June SU of this year? We have some organizations where the migration to SE or Exchange Online is not yet completed.

    • Nino_Bilic's avatar
      Nino_Bilic
      Icon for Microsoft rankMicrosoft
      Oct 01, 2026

      Yes, if you are up to date with ESU updates then those services will keep on working. We have no intention to break those services on purpose. The "break" that happened over the last few months was due to certificate expiration.

  • Dennisdsmolinski's avatar
    Dennisdsmolinski
    Brass Contributor
    Jul 29, 2026

    Hi Nino.

    Has a timeline been established as yet for the requirement for Exchange SE servers to have for Exchange SE Dedicated License Keys

    • LIRO-Bwi's avatar
      LIRO-Bwi
      Brass Contributor
      Jul 31, 2026

      Hi,
      I´m not Nino - don´t know why he didn´t answer, may be due to  the volume of messages - here is the article of Scott for SE Licensing. Nobody has updated this, so I think it is still the base ... Exchange Server SE Licensing and Product Keys | Microsoft Community Hub

      It is expected that new product keys specific to Exchange Server SE will be made available with Exchange Server SE CU1

      • Nino_Bilic's avatar
        Nino_Bilic
        Icon for Microsoft rankMicrosoft
        Jul 31, 2026

        Thanks for answering!

        True story: for some reason, my notifications for new comments / questions on the blog have been working very inconsistently. I still have not figured out what changed... sigh.

  • Sevenlager's avatar
    Sevenlager
    Copper Contributor
    Jul 28, 2026

    Hi guys,

    Thank you for sharing, but I have a question. Will the mixed deployment of these versions be affected after ESU ends?

    • Nino_Bilic's avatar
      Nino_Bilic
      Icon for Microsoft rankMicrosoft
      Jul 29, 2026

      After ESU ends (and no more updates are available for Exchange 2016/2019 to any customers) - the expectation should be that any Exchange 2016/2019 servers will be stay out of date and as time goes on, will become more and more outdated as time goes on. This might manifest itself in not just vulnerabilities of those servers, but also possibly things that do not work properly between Exchange SE servers (which will still receive updates as supported product) and Exchange 2016/2019 servers that will be out of date.

      I might not have fully understood your question, please clarify if the above does not cover it.