Microsoft has experienced a widespread global outage, disrupting access to Outlook, Teams, Copilot and other Microsoft 365 services, with businesses, government agencies and schools across several countries affected.
The disruption began around midday on Thursday, November 12, in the United States and continued into Friday, preventing users from accessing email accounts, sending and receiving messages and using other cloud-based workplace services.
Microsoft said it was working to restore the affected infrastructure after identifying server availability issues and an overwhelmed process on the impacted servers.
The disruption affected several Microsoft 365 services, including Outlook, Teams, Copilot and SharePoint, leaving users unable to access essential workplace tools.
Services relying on Exchange Online, Microsoft’s email platform, were among the hardest hit, although some features that do not depend on the service continued to function.
The scale of the disruption was reflected in reports submitted to Downdetector, a platform that tracks service outages.
At the peak of the disruption in the United States, Downdetector recorded more than 130,000 reports of problems accessing Outlook. However, the figure represents user-submitted reports and does not indicate the confirmed number of customers affected.
The outage was reported in several countries, disrupting operations across businesses, government agencies and educational institutions.
In Australia, some businesses were unable to print invoices, while several schools experienced difficulties conducting online classes. Court livestreaming services were also disrupted, forcing some schools to ask parents to report student absences through phone calls.
The outage also affected other sectors. Reuters reported that email support services used by Indian airlines IndiGo and Akasa Air were disrupted, while some financial institutions in Taiwan experienced interruptions to their fund management operations.
The outage also affected Microsoft connectors used by OpenAI and Anthropic, disrupting their integration with Microsoft 365 services.
Microsoft initially blamed the disruption on increased infrastructure loads across multiple regions. However, the company later clarified that the problem was not caused by a general surge in traffic but by an unexpected loss of availability across a large number of servers, shifting demand to the remaining infrastructure.
Further investigations revealed that a core process running on the affected servers had become overwhelmed, causing them to stop responding and further reducing available capacity.
