Microsoft Starts Disabling EWS, Putting Mac Mail Sync With 365 at Risk

Microsoft has begun disabling Exchange Web Services (EWS) by default in Exchange Online. That could break synchronization for Apple's Mail and Calendar apps on Mac, which still rely on the protocol for Microsoft 365 work accounts.

The change will roll out in stages, so users may lose access at different times. Organizations that have kept EWS enabled are not affected for now.

Microsoft plans to shut down EWS permanently on April 1, 2027, and says no extensions are currently planned.

Apple is preparing a Graph API migration

Apple says it is working with Microsoft to move Mail, Calendar, Contacts, Notes and Reminders on Mac to the newer Microsoft Graph API in a future macOS 27 update. That support has not appeared yet: Apple skipped macOS 27.1 betas, and macOS 27.2 beta release notes do not mention Graph support.

IT administrators can currently restore access by keeping EWS enabled or move Mac users to a Graph-compatible client such as Microsoft's Outlook app.

The change applies only to Microsoft's cloud-hosted email service. Companies running their own Exchange servers are not affected, nor are iPhone and iPad users, whose devices use Exchange ActiveSync rather than EWS.