Microsoft has announced to retire the Exchange Web Services (EWS) API for Exchange Online and Office 365 by October 2026. This move comes after a series of announcements and changes related to the EWS platform over the past few years.
EWS: A Brief Overview
The Exchange Web Services (EWS) API has been a staple for developers, providing a cross-platform interface to develop applications that can access mailbox items such as emails, meetings, and contacts. These items can be sourced from various platforms, including Exchange Online, Office 365, and on-premises versions of Exchange, starting from Exchange Server 2007. However, Microsoft's recent announcement indicates a shift in focus, emphasizing the transition to other platforms.
Transitioning to Microsoft Graph API
Developers utilizing the EWS API are now being advised to transition to the Microsoft Graph API. This new platform will also grant access to Exchange Online data. Despite this, Microsoft has acknowledged certain feature gaps between EWS and Microsoft Graph. Some of the most notable gaps include the inability to access archive mailboxes, lack of folder-associated information, absence of Exchange Online management capabilities, and no third-party application access to Exchange Online public folders. While Microsoft is actively working to bridge these gaps, developers might need to seek alternatives for certain features that may not be integrated into the Graph API.
The retirement of EWS is exclusive to Microsoft 365 and Exchange Online across all environments. It's crucial to note that no alterations are being made to EWS within the Exchange Server. Furthermore, the changes planned for Exchange Online will not affect other Microsoft products such as Outlook for Windows or Mac, Teams, and others. The existing EWS components will still receive security and some non-security updates, but there will be no modifications to the product's design or features.
The Long-Term Vision
Microsoft's decision to retire EWS and promote the Microsoft Graph API aligns with their long-term vision. This move is seen as a step towards ensuring more secure, reliable, and efficient experiences for both developers and end-users. The company has expressed its commitment to assisting affected users during this transition, promising regular communications leading up to the 2026 deadline.
“…we are confident it will ensure more secure, reliable, and performant experiences,” the Exchange Team commented on the upcoming changes. They also expressed gratitude in advance for developers and organizations willing to adapt and explore the broader range of features available on Microsoft Graph.
This announcement is a continuation of Microsoft's stance from August 2018 when they cautioned developers about the cessation of investments in the EWS APIs for Exchange Online. Fast forward to October 2021, Microsoft declared the deprecation of the 25 least used APIs of EWS for Exchange Online, subsequently removing support for these deprecated APIs in March 2022 for security reasons.