A major technical failure in Microsoft’s infrastructure disrupted Outlook, Teams, Copilot, and several Microsoft 365 services on November 12, affecting users across more than 70 countries.
The outage began with problems in Exchange Online, leaving millions unable to access emails, send messages or receive updates. Services such as Teams calendars, SharePoint, Planner and Power BI also experienced disruptions.
Microsoft traced the issue to a network-related problem that reduced server availability. A process responsible for establishing secure connections became overwhelmed, preventing affected servers from handling requests. The company ruled out cyberattacks and AI-related failures.
The disruption also affected businesses and airlines. In India, IndiGo warned passengers that its email support system was impacted. OpenAI and Anthropic also reported issues with their Microsoft 365 connectors.
Restoring services proved challenging as some servers became unresponsive again after restarting. Microsoft gradually redirected traffic, increased capacity and reversed network changes to stabilise operations.
By November 14, most affected services had recovered. However, Microsoft continued monitoring systems and processing delayed emails. The company apologised and promised a detailed report explaining the incident and measures to prevent future disruptions.