Microsoft is retiring Exchange Web Services (EWS) in Exchange Online, with the final shutdown scheduled for October 1, 2026. This marks the end of a protocol that has been central to email integrations and migration tools for nearly two decades. See also Enforcement of Multi-Factor Authentication in Microsoft 365 tenants: Implications and Preparations.
The EWS retirement applies only to Exchange Online (Microsoft 365). EWS in Exchange Server on-premises is not affected.
Complete EWS Retirement Timeline
Here's the complete schedule for the EWS retirement:
- July 2018 — Deprecation announced, no new features, security patches only
- 2021-2022 — 25 least used EWS APIs deprecated and removed
- April-October 2025 — Temporary EWS outages and tightened controls begin
- March 1, 2026 — F1, F3, and Kiosk licenses blocked from EWS
- October 1, 2026 — EWS completely disabled for all Exchange Online tenants
Why Microsoft is Retiring EWS
The decision is driven by several factors:
- Security Concerns: The Midnight Blizzard security incident in January 2024 elevated the urgency
- Modern Architecture: Microsoft Graph API offers a unified, REST-based endpoint with better security
- Reduced Maintenance: Maintaining legacy SOAP-based protocols increases complexity
Following the January 2024 security incident, Microsoft expanded the EWS retirement scope to include all applications.
What's Affected (and What's Not)
Affected by EWS Retirement
- Third-party applications using EWS
- Custom integrations and scripts
- Migration tools
- Calendar sync applications
- Email archiving solutions
- CRM and helpdesk integrations
NOT Affected
- Outlook for Windows/Mac
- Microsoft Teams
- Outlook mobile apps
- Microsoft 365 Apps
- Exchange Server on-premises
Starting March 1, 2026, users with F1, F3, and Kiosk licenses will be blocked from EWS access — earlier than the general October deadline.
Migration to Microsoft Graph API
Microsoft Graph API is the recommended replacement. However, the transition is not always straightforward.
Graph API Advantages
- Unified endpoint for all M365 services
- Modern REST architecture
- OAuth 2.0 & conditional access
- Active development & updates
Current Limitations
- Tasks: Limited support (To Do API)
- Public folders: Partial support
- Streaming notifications: Webhooks only
How to Prepare
Follow these steps to prepare:
Inventory Applications
Identify all applications using EWS. Use Microsoft's EWS Usage Reports.
Assess Graph Readiness
Determine if Graph API supports required functionality.
Check Licenses
F1, F3, and Kiosk licenses lose EWS access in March 2026.
Contact Vendors
Understand third-party vendors' Graph API migration plans.
Test Early
Start testing Graph API integrations now.
Planning a Migration?
Cloudiway is ready for the EWS retirement. Contact us to discuss your migration project.
Frequently Asked Questions
When will Microsoft disable Exchange Web Services (EWS)?
Microsoft will begin blocking EWS requests to Exchange Online on October 1, 2026. However, organizations using F1, F3, or Kiosk licenses will be blocked starting March 1, 2026. Exchange Server on-premises is not impacted.
Does EWS retirement affect Exchange Server on-premises?
No, the EWS retirement only applies to Microsoft 365 and Exchange Online. There are no changes to EWS in Exchange Server on-premises deployments.
What should I use instead of EWS?
Microsoft recommends migrating to Microsoft Graph API as the replacement for EWS. Graph API provides modern REST-based access to Exchange Online data including mail, calendar, contacts, and tasks.
Will Outlook be affected by EWS retirement?
No, Outlook for Windows, Mac, Teams, and other Microsoft products are not affected. Microsoft is updating its own applications to use modern APIs internally.
Does EWS retirement affect cloud migrations?
Yes, migration tools that rely on EWS need to transition to Microsoft Graph API. Migration vendors like Cloudiway are updating their platforms before the October 2026 deadline.
