
Auth glitches halt Microsoft 365 services, hitting Exchange Online and linked apps
Microsoft is investigating a widespread outage causing authentication failures, connectivity issues, and email delays in Exchange Online, with broader impact on OneDrive for Business, SharePoint Online, Teams, Purview, and Defender XDR. The incident, tracked as MO1465074 (formerly EX1464935), affects tens of thousands of users per Downdetector. Microsoft says a common authentication/protocol failure pattern is under investigation and notes a core authentication configuration issue is being addressed with manual server resets as the scope and remediation continue.













