After years of warnings and delays, Microsoft is finally shutting down Exchange Web Services (EWS) in its cloud-based Exchange Online platform. This change is set to happen gradually, with the API being disabled by default starting October 1, 2026, and completely retired by April 1, 2027. Organizations using EWS need to switch to Microsoft Graph to avoid disruptions, as there are no exceptions to this plan. Admins can extend their EWS access slightly if they make specific configuration changes and create allow lists, but they must do so before the end of August 2026.

What EWS Means and Why It’s Going Away

Exchange Web Services has been a key API for developers connecting third-party apps and internal tools to Exchange Online and older on-premises versions. It allows access to mailbox items like emails, contacts, and calendars. EWS has been popular among system integrators and third-party vendors because it provides a way to connect to Exchange data across platforms. However, Microsoft announced its deprecation almost a decade ago, and it’s been clear for years that EWS would eventually be phased out. The last official warning came in 2023, when Microsoft announced that EWS would be fully disabled in Exchange Online by October 2026.

The retirement process is part of a broader effort to streamline Microsoft’s platform and encourage modern development. Microsoft wants users and developers to transition to Microsoft Graph, a newer API platform introduced in 2015. Graph offers many of the same features as EWS but is more secure, scalable, and compatible with modern cloud services. Microsoft states that Graph has achieved “near-complete feature parity” with EWS for most common use cases. Many Microsoft apps have already migrated or are close to completing the switch, and third-party vendors are also making the move.

The Transition to Microsoft Graph

Replacing EWS with Microsoft Graph is designed to simplify how developers connect with Microsoft 365, Windows, and Azure. Graph supports cross-platform connectivity, including iOS and Android, making it a more flexible choice. Microsoft emphasizes that moving to Graph will reduce legacy code and improve overall security and reliability.

Organizations have a window of time to prepare for this change. They can adjust settings and create allow lists to extend EWS access until August 2026, but after that, access will be entirely cut off. Microsoft describes this process as a “phased, admin controllable disablement plan,” giving IT teams some control over the transition. The goal is to encourage everyone to adopt the new API before the final shutdown, avoiding potential disruptions to workflows and integrations.

Microsoft’s push to retire EWS reflects its broader strategy to modernize its cloud platform. The company believes that Graph offers a better experience aligned with today’s security standards and cloud architecture. For organizations still relying heavily on EWS, this change means planning a migration to ensure continued access to mailbox data and functions in Microsoft 365. The transition may involve updating applications, scripts, and third-party tools to work with the new API platform.

Inspired by

• https://www.computerworld.com/article/4129036/after-years-of-warnings-microsoft-is-finally-pulling-the-plug-on-ews.html

Sources

• infotech.com
• microsoft.com
• csoonline.com
• microsoft.com