A widespread outage affecting Microsoft 365 services began on the afternoon of 12 November 2026 and continued into Friday morning, leaving millions of users around the world unable to reliably access email, collaboration tools and other cloud applications.
The disruption started at approximately 16:17 UTC on 12 November, according to Microsoft’s service health dashboard. It centred on Exchange Online and rapidly spread to related services. Users reported being unable to access mailboxes via Outlook on the web, desktop or mobile clients, with email delivery delays. Other heavily affected products included Microsoft Teams (particularly calendar and scheduling features), SharePoint Online, Microsoft 365 Copilot, and various security and productivity tools such as parts of Defender and Power BI.
Outage-tracking site Downdetector recorded reports from 74 countries and territories within about an hour. Peak problem reports for Outlook approached 130,000 to 140,000 globally. Banks, government agencies, schools, courts and businesses in regions including the United States, Australia, Hong Kong, the UK and parts of Asia reported significant disruption to daily operations.
Microsoft attributed the incident to infrastructure problems rather than a cyber attack. Servers failed automated health checks and became unavailable, creating elevated load across remaining systems. A process responsible for establishing secure connections became overwhelmed on affected servers. Charles Lamanna, an executive vice president at Microsoft, confirmed there was “no indication this is the result of malicious or cyber activity.”
The company issued a series of status updates throughout the evening and overnight. Early mitigation efforts initially showed positive signs, but Microsoft later stated that changes were “not taking as expected” and that it had not achieved sustained recovery. Engineers worked on restarting servers, applying alternative health-check methods, rerouting traffic, scaling virtual machines to increase capacity, and limiting certain traffic types to stabilise systems. Partial recovery was observed in some regions, yet problems persisted for many users.
By the morning of 13 November UTC, the outage had lasted more than 15 hours. Core messaging and some online meeting functions in Teams remained largely available in many cases, while Exchange-dependent features continued to cause issues. Related impacts were noted on connectors used by external AI services. Microsoft continued monitoring and expanding corrective measures, advising customers that recovery would be gradual as capacity returned and clients reconnected.
The incident highlights the heavy reliance of organisations worldwide on Microsoft’s cloud productivity suite. The company has not provided a firm timeline for full restoration and continues to post updates via its official status channels.
