Microsoft Launches Subscription Edition of Local Exchange Server

Microsoft has officially released the Subscription Edition of its local Exchange Server, marking the successor to the last locally installable version, Exchange Server 2019. This new iteration maintains an on-premises option for users, allowing them to choose between migrating to the cloud with Microsoft 365 or Exchange Online, or implementing a hybrid deployment that combines both options.

In a recent blog post, Microsoft's Exchange development team announced the general availability of the Subscription Edition. As Exchange Server 2016 and 2019, along with Windows 10, are set to reach their end of support on October 14, 2025, transitioning to the latest version is essential. Cybercriminals frequently target vulnerabilities in older Exchange servers, making timely upgrades critical for security.

The migration from Exchange Server 2019 CU14 or CU15 to the new Subscription Edition can be executed as a cumulative update. Microsoft has indicated that this process is designed to be straightforward, similar to the transition from Windows 11 24H2 to 25H2 via Enablement Packages. The Subscription Edition is intended to integrate into existing Exchange 2016 and 2019 environments, although a traditional mailbox migration is required for Exchange 2016.

Furthermore, the migration process will transition the local Exchange Server into the 'Modern Support Lifecycle,' a model that promises continuous development and support from Microsoft, provided customers maintain the latest version. Unlike previous releases, the Subscription Edition does not involve extensive code modifications or changes compared to Exchange 2019, leading Microsoft to assess a low-risk profile for an in-place upgrade.

Key differences in the new Subscription Edition include revised licensing terms, a name change from Microsoft Exchange Server 2019 to Microsoft Exchange Server Subscription Edition, and updated build and version numbers (Subscription Edition RTM: 15.02.2562.017). Updates released since Exchange 2019 CU15 will also be incorporated into the Subscription Edition, maintaining consistency with future cumulative updates.

Microsoft emphasizes that the RTM release of the Subscription Edition mirrors Exchange 2019 CU5, aside from the aforementioned distinctions. As support for Exchange 2016 and 2019 concludes, the Subscription Edition will be the sole supported on-premises version, allowing Microsoft to streamline and modernize the product over the coming years. The company aims to deliver two cumulative updates per year, along with security patches and hotfixes as necessary.

Organizations are encouraged to migrate to the Subscription Edition promptly, as older Exchange 2016 and 2019 servers will not be supported with CU2 for the Subscription Edition. Future updates will modernize installation prerequisites, requiring Subscription Edition server keys and introducing new functionalities.

In addition, Microsoft has recently made the Skype for Business Server Subscription Edition available for those with multiple on-premises server requirements, suggesting ongoing support for the platform despite previous announcements regarding discontinuation.