As October 2025 approaches, the end of support for Microsoft Exchange 2016 and 2019 raises significant concerns for organizations relying on these technologies. With no extended support updates planned, businesses face critical decisions as the phase-out nears.
Organizations still wanting to maintain an on-premises solution can transition to Microsoft’s Exchange Server Subscription Edition (SE), which will launch alongside the discontinuation of the previous versions. This edition will share code with Exchange Server 2019 CU15 but with updated licensing agreement terms and version numbers. It’s essential to understand that upgrading to Exchange SE involves either an in-place upgrade or a more extensive migration process, often requiring careful planning to limit disruptions.
An important point to note is that multiple versions of Exchange cannot coexist; all servers need to be updated to Exchange SE. For users currently on unsupported versions like Exchange 2013, a two-step upgrade process is necessary, moving first to Exchange 2019 before upgrading to Exchange SE.
Maintaining an on-premises Exchange environment is becoming increasingly challenging amidst evolving security vulnerabilities and the need for constant updates. With the complexity of patching and integrating with cloud-based tools, many organizations are considering a shift towards Microsoft 365, where the maintenance burden shifts to the software provider.
If an organization opts to retain on-premises servers, now is the time to analyze whether the internal resources and expertise are sufficient to sustain support. The viability of continuing with an obsolete platform is dwindling, with Microsoft enforcing limits that restrict older servers from interacting with newer environments.
Organizations must evaluate their operational needs and prepare for potential transitions to Exchange SE or cloud solutions. The upcoming changes symbolize a critical inflection point that requires thorough analysis of technological needs and strategic infrastructure planning. Ultimately, the decision now can shape the long-term effectiveness and security of an organization’s communication systems.
For those considering migration, reviewing security benchmarks and best practices for cloud deployment could be beneficial, especially in the wake of past incidents encouraging shifts towards cloud solutions.