Overview
- The outage began on Thursday and quickly stopped many users from signing in, sending or receiving email on Outlook and using Microsoft 365 apps such as Teams, SharePoint, OneDrive and Copilot.
- Monitoring site DownDetector logged spikes of user reports with Outlook peaking at about 100,000 reports and Microsoft 365 tens of thousands of reports as the problem spread to roughly 74 countries.
- Microsoft said the interruption was not a cyberattack but resulted from a large number of servers failing automated health checks which overloaded remaining capacity and propagated failures.
- Engineers paused routine changes, redistributed connection traffic, restarted affected servers and deployed alternate health‑check mechanisms while some regions show partial recovery but global restoration remained incomplete after many hours.
- The outage disrupted banks, airlines and government offices, prompted airline advisories and raised fresh questions about reliance on a small number of cloud providers after Microsoft’s third major 2026 incident and before the company issues a full post‑incident report.