# Exchange Server 2016 and 2019 have been out of support since October 14, 2025: move to Exchange SE or online > Microsoft’s lifecycle pages show Exchange Server 2016 and 2019 reached end of support on October 14, 2025, after which there are no new security updates or assisted support. Exchange Server Subscription Edition, which started July 1, 2025 under the Modern Lifecycle Policy, is listed as in support. - Canonical URL: https://update.dsesecurity.com/updates/exchange-server-2016-2019-end-of-support-subscription-edition-upgrade/ - Publisher: Detection Systems & Engineering (DSE Security) - Author: DSE Security Editorial Team - Published: 2026-10-18T21:01:17+00:00 - Modified: 2026-10-18T22:22:08+00:00 - Last reviewed by DSE: 2026-10-18 - Resource type: Briefing - DSE priority: Important - Topics: IT, Microsoft 365 & Identity - Reading time: 2 minutes ## What you need to know Microsoft’s lifecycle pages show Exchange Server 2016 and 2019 reached end of support on October 14, 2025, after which there are no new security updates or assisted support. Exchange Server Subscription Edition, which started July 1, 2025 under the Modern Lifecycle Policy, is listed as in support. ## Potentially affected Organizations still running on-premises Exchange Server 2016 or 2019, including servers kept for hybrid management or SMTP relay, and the providers who maintain them. ## DSE recommendation DSE recommends retiring or upgrading every Exchange Server 2016 and 2019 installation, and treating any that remain as unpatched servers until they are gone. ## Article Microsoft’s lifecycle pages show Exchange Server 2016 and 2019 reached end of support on October 14, 2025, after which there are no new security updates or assisted support. Exchange Server Subscription Edition, which started July 1, 2025 under the Modern Lifecycle Policy, is listed as in support. ## Source facts Microsoft’s lifecycle pages for [Exchange Server 2019](https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-2019) and [Exchange Server 2016](https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-2016) show both follow the Fixed Lifecycle Policy, with mainstream support ending in January 2024 for 2019 and in October 2020 for 2016. Microsoft’s [list of products ending support in 2025](https://learn.microsoft.com/en-us/lifecycle/end-of-support/end-of-support-2025) shows both reaching end of support on October 14, 2025. That list says that upon retirement or end of support there are no new security updates, non-security updates, free or paid assisted support options or online technical content updates. The Exchange Server 2016 page tells customers to move to the most recent cumulative update for Exchange Server 2019 to be prepared for an in-place upgrade to Exchange Server SE. Microsoft’s [Exchange Server Subscription Edition lifecycle page](https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-subscription-edition) shows it follows the Modern Lifecycle Policy, with a start date of July 1, 2025, and lists it as in support. ## Applicability Use this for any organization with on-premises Exchange servers, including servers kept only for hybrid management or relay. Licensing for Exchange Server SE and migration paths to Exchange Online vary; confirm them with Microsoft or a licensing partner. ## DSE recommendation DSE recommends retiring or upgrading every Exchange Server 2016 and 2019 installation, and treating any that remain as unpatched servers until they are gone. Move mailboxes to Exchange Online or Exchange Server SE, bring Exchange 2019 to its latest cumulative update before an in-place upgrade, repoint scanners, alarm panels and applications that relay through Exchange, and restrict any remaining server to internal access. ## Verification Inventory Exchange servers and their versions, confirm each is retired or on Exchange Server SE, and check that no DNS records, firewall rules or connectors still point to retired servers. ## Official references [Microsoft Lifecycle — Exchange Server 2019](https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-2019). [Microsoft Lifecycle — Exchange Server 2016](https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-2016). [Microsoft Lifecycle — Ending Support in 2025](https://learn.microsoft.com/en-us/lifecycle/end-of-support/end-of-support-2025). [Microsoft Lifecycle — Exchange Server Subscription Edition](https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-subscription-edition). Reviewed October 18, 2026. ## Primary reference - Name: Microsoft Lifecycle — Exchange Server 2019 - Authority: Microsoft Learn - URL: https://learn.microsoft.com/en-us/lifecycle/products/exchange-server-2019 - Source publication date: Not stated by the source ## Citation and use Preferred citation: “Exchange Server 2016 and 2019 have been out of support since October 14, 2025: move to Exchange SE or online,” DSE Security, https://update.dsesecurity.com/updates/exchange-server-2016-2019-end-of-support-subscription-edition-upgrade/ Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/ Usage and citation policy: https://update.dsesecurity.com/usage/ Copyright © 2026 Detection Systems & Engineering. All rights reserved.