Microsoft Extends ESU Support for Skype for Business and Exchange Servers

Microsoft is continuing to support legacy enterprise products through its Extended Security Updates (ESU) program, with renewed focus on Skype for Business Server and Exchange Server 2016/2019 deployments.

The move comes alongside ongoing ESU activity, including recent updates like KB5082200, with Microsoft also extending the program to Windows 10 Enterprise 2016 LTSB. This reflects a broader effort to keep critical business infrastructure secure while organizations transition to newer platforms.

ESU program expands support for Skype and Exchange

Microsoft confirmed that its ESU program covers key enterprise services, including Skype for Business Server and Exchange Server 2016 / Exchange Server 2019. These platforms remain widely used in corporate environments, making extended security coverage essential for organizations not ready to migrate.

These updates are limited in scope and include only critical security patches and important vulnerability fixes.

Each phase operates independently, meaning organizations must enroll separately. Purchasing access to Period 1 does not automatically grant access to Period 2.

How the ESU program works

Unlike standard updates, ESU patches are not publicly distributed. Microsoft delivers them directly to eligible organizations.

These updates are limited in scope and include only:

• Critical security patches
• Important vulnerability fixes

There is no guarantee of regular update frequency, and organizations may go extended periods without receiving new patches.

Limitations and eligibility

Microsoft positions ESU as a temporary bridge rather than a long-term solution. The program is designed to give businesses time to plan migrations without exposing systems to major security risks.

However, access is restricted. ESU is not available through Volume Licensing or Software Assurance. Only commercial customers with a Microsoft Enterprise Agreement (EA) can purchase it.

Exchange Server support timeline extended

In a separate update, Microsoft confirmed that Exchange Server will continue receiving support until 2035. This provides a significantly longer runway for enterprises still relying on on-premises email infrastructure.

Microsoft pushes for migration

Despite extending support, Microsoft continues to encourage organizations to move to newer solutions. ESU exists primarily to reduce risk during transition periods, not to replace long-term upgrades.

Companies relying on Skype for Business Server or older Exchange deployments will need to plan carefully, as ESU coverage remains limited in both scope and duration.

Via Neowin