Table of Contents
Summary
- Exchange Web Services (EWS) will be retired in favor of Microsoft Graph, enhancing security and capabilities.
- Organizations using EWS for custom apps or workflows will need to take action to avoid service disruptions.
- Admins can block EWS unless configured with an AppID AllowList and EWSEnabled=True.
- Migrating to Microsoft Graph is recommended to maintain functionality with near-complete API parity.
- Communication within organizations and documentation updates are essential to prepare for this change.
Admin Impact: High
User Impact: Medium
Release Start: 01 Oct 2026
Release End: 01 Apr 2027
Services: Exchange
Category: Plan for change
Tags: User Adoption, Admin Action, Retirement
History
2/5/2026 Item Added to Message Center
Microsoft Message
Introduction
We’re updating the timeline and process for the retirement of Exchange Web Services (EWS) in Exchange Online. As previously announced, EWS will be retired in favor of Microsoft Graph, which offers improved security, modern authentication, and broader capability support. A phased disablement begins October 1, 2026, with permanent shutdown starting April 1, 2027.
When this will happen
- Phased EWS disablement begins: October 1, 2026
- Full and permanent EWS retirement: April 1, 2027
- EWS App AllowList feature availability: Coming soon (before retirement milestones)
How this affects your organization
Who is affected:
- Organizations using custom or vendor applications that rely on EWS
- Workflows involving mail, calendar, or integrations that use EWS
- This change only impacts Exchange Online; Exchange Server (on-premises) is not affected
What will happen:
- Beginning October 1, 2026, EWS will be blocked unless the tenant configures an AppID AllowList and sets EWSEnabled=True.
- Without admin action, Microsoft will set EWSEnabled=False and EWS apps will stop working. Tenant admins will be able to re-enable EWS if necessary.
- Temporary “scream tests” may occur before October 2026 to help identify dependencies.
- After April 1, 2027, EWS access will be permanently removed with no re-enablement.
- No changes are being made to EWS in Exchange Server (on-premises).
What you can do to prepare
- Review EWS usage in the Microsoft 365 admin center or using published scripts to identify dependent applications.
- Begin migrating any remaining EWS-based workflows to Microsoft Graph, which provides near-complete API parity.
- If EWS is required after October 2026, configure an AppID AllowList and set EWSEnabled=True before end of August 2026.
- Communicate these changes internally and update documentation.
Learn more:
- Deprecation of Exchange Web Services in Exchange Online
- EWS Retirement Process overview
Compliance considerations
No compliance considerations identified, review as appropriate for your organization.