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Deprecation of Exchange Web Services in Exchange Online

In 2018, we announced that Exchange Web Services (EWS) will no longer receive functionality updates. In 2023, we announced that EWS will be disabled in Exchange Online in October 2026.

The Midnight Blizzard security incident in January 2024 involved EWS and elevated the urgency of the EWS deprecation effort. The scope was also widened from third party applications to include all Microsoft applications. We're working diligently to remove EWS dependencies in all Microsoft products. For example:

  • Microsoft Outlook
  • Microsoft Office
  • Microsoft Teams
  • Microsoft Dynamics 365

This work accelerated the need to close parity gaps between EWS and Microsoft Graph for many scenarios. Other efforts are underway in the following scenarios:

  • Close the remaining parity gaps that affect specific scenarios for third party applications.
  • Provide guidance for alternative solutions.

To learn if your third party applications use EWS, see this article.

Many application scenarios are already supported with direct mappings between EWS operations and Graph APIs.

To move your organization to a stronger security posture, we recommend identifying your active EWS applications and starting their migration now.

To simplify and accelerate your analysis and migration, we introduced the EWS Usage Reports, the EWS Analyzer tool, and a tutorial for AI assisted code analysis and refactoring.

Roadmap for parity gaps

There are a few major EWS features areas that the Microsoft Graph API doesn't fully support. The priority of work to close these feature gaps is described in the following list:

EWS deprecation timeline

Call To Action

Don't wait for all parity gaps to be closed. You can be proactive by doing the following steps:

  • Investigate the EWS footprint of all internal and third party applications in your organization. Start with EWS Usage Reports (direct link).
  • Work with your security and executive teams to prioritize EWS deprecation for internal applications.
  • Identify applications and components you can migrate now and start the implementation. Use the EWS Analyzer tool and AI assistance to analyze and refactor EWS code or reimplement in low-code approach with Power Platform or as a Copilot Agent.
  • Work with your vendors to prioritize their migration from EWS.

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