Mac Users Face Microsoft 365 Sync Issues as EWS Phased Out

If you or your users rely on Apple Mail on macOS to access Microsoft 365 work or school accounts, you may soon run into unexpected sync disruptions. Starting October 1, 2026, Microsoft began disabling Exchange Web Services (EWS) by default in Exchange Online as part of a phased rollout ahead of a complete, permanent shutdown on April 1, 2027. Because Apple’s native Mac apps (including Mail, Calendar, Contacts, Notes, and Reminders) still rely on EWS to communicate with Exchange Online, Mac users are likely going to start to find themselves locked out of their mailboxes.This change strictly affects cloud-hosted Microsoft 365 accounts on macOS. On-prem Exchange servers are unaffected, as are iPhones and iPads, which connect using Exchange ActiveSync rather than EWS. Apple is currently working with Microsoft to migrate its desktop apps to the modern Microsoft Graph API in a future macOS release, though an official release date for the patch has not yet been announced.In the interim, IT…