Exchange 2016 and 2019 Will Go Without Security Updates from November

Microsoft has reminded customers that October 2026 will mark the end of security updates for Exchange Server 2016 and 2019 under the Extended Security Updates (ESU) program. After that, servers running these versions will stop receiving any fixes at all — even for those who signed up for the current ESU period.

Both editions moved beyond their mainstream lifecycle long ago: mainstream support for Exchange 2016 ended in October 2020, and for Exchange 2019 in January 2024. The ESU program launched in October, when both versions reached end of support, and in April 2026 Microsoft added a six-month extension to it — the so-called “second period.”

No More Extensions

In a blog post, the Exchange Server team gave a direct answer to the increasingly frequent questions about a possible new extension. The company acknowledges the irony of the situation: the original announcement stated there would be no extensions, yet that very “second period,” expiring in October 2026, appeared afterward. It is now roughly halfway through.

“There will be no further extension of the ESU program timelines for Exchange 2016/2019. Once October 2026 ends, no more updates for Exchange 2016/2019 will be released — even if you currently have a valid second-period ESU,” the statement reads.

What Administrators Should Do

Microsoft advises moving to Exchange Server Subscription Edition (SE). For those already running Exchange 2019, an in-place upgrade is available — the procedure is identical to installing a cumulative update (CU). Administrators still running Exchange 2016 or even 2013 in production are advised either to move straight to SE or to install Exchange 2019 first. As an alternative, migration to cloud-based Exchange Online is offered — either as a standalone service or as part of a Microsoft 365 subscription.

This isn't the only recent news from Microsoft about support timelines. In June, the company quietly extended the free ESU program for consumer Windows 10 by another year — through October 2027. And in early July it announced that Windows Server 2022 and the Home and Pro editions of Windows 11 24H2 would reach end of support in 90 days, but would move into extended mode and continue receiving security updates.

Source: Bleeping Computer