Updated: June 27, 2025 (February 14, 2025)

Exchange Server: Migrate Off Legacy Versions by Oct. 2025

As managing vice president, Rob Helm covers Microsoft collaboration and content management. His 25-plus years of experience analyzing Microsoft’s technology... more

Exchange Server 2016 and 2019 customers will have 90 days or less under product support to migrate to Exchange Server SE, the next version.

All existing versions lose product support by Oct. 14, 2025.

The shortest upgrade path runs through Exchange Server 2019.

Long-term, IT leaders should look for exits from Exchange Server to Exchange Online, or off Exchange entirely.

Exchange Server customers should expect higher subscription fees, more frequent update rollouts, and some to Exchange Server Subscription Edition (SE), the next version. There is no supported alternative: On Oct. 14, 2025, all other versions of Exchange Server leave support.

June 27, 2025: Updated with the latest plans for Cumulative Updates and a hard deadline for migration in the second half of 2026.

Near Term (2025)

The next version of Exchange Server, Exchange Server SE, should ship in the third quarter of 2025. Microsoft says that Exchange Server SE will be “code equivalent” to Exchange Server 2019 with Cumulative Update (CU15, released Feb. 2025) and the latest security updates. The main differences will be branding and licensing. (See “Exchange Server Cumulative Updates” for an explanation of CUs).

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