Urgent Update: End of Support for Microsoft Exchange 2016 and 2019 Imminent
Microsoft has officially announced that both Exchange 2016 and Exchange 2019 will reach their end of support on October 14. With the deadline just six months away, users are urged to prepare for necessary transitions.
Security Risks and Challenges Ahead
The Exchange Server Engineering Team strongly advises administrators tasked with decommissioning these servers to act swiftly, highlighting that post-support, these versions will be vulnerable to security threats due to the lack of security patches and bug fixes.
Although installations of Exchange 2016 and 2019 will continue to operate post-October 14, 2025, Microsoft cautions that using these unsupported versions could pose serious security risks. Prompt action is recommended to mitigate potential threats.
Previous Communications and Decisions
Earlier in the year, Microsoft reiterated to IT administrators the impending end of technical support for these servers starting October. Additionally, there will be no extension of the end-of-life date, nor will there be extended support or Extended Security Updates (ESU) available after May 2024.
This follows the end of mainstream support for Exchange 2019 on January 9, 2024, and for Exchange 2016 in October 2020.
Migration Options: Exchange Online and Exchange Server SE
Microsoft is guiding Exchange administrators towards upgrading or migrating their systems. Options include transitioning to the forthcoming Exchange Server Subscription Edition (SE) or migrating to Exchange Online, which is available either as a standalone service or as part of an Office 365 subscription.
Upgrade Paths Explained
For those opting to retain their Exchange server setups:
- Admins can perform in-place upgrades from Exchange Server 2019 to Exchange Server SE.
- For Exchange 2016 users, Microsoft recommends a legacy upgrade to Exchange 2019 followed by an in-place upgrade to Exchange Server SE upon its release.
- Alternatively, users of Exchange 2016 can opt for a direct legacy upgrade to Exchange Server SE RTM, bypassing Exchange 2019 entirely, although this could be challenging due to the limited time before support cessation.
Microsoft has also provided comprehensive guidance for global admins on migrating to Microsoft 365 and detailing the Exchange Online migration path to assist organizations in this transition.
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Last Updated: April 15, 2025
