The key facts

  • The global outage affected Outlook, Teams, Copilot and other Microsoft 365 services in 74 countries.
  • The cause was cited as the unavailability of a large number of servers, not a cyberattack or traffic surge.
  • The incident forced the postponement of financial reports and disrupted the operations of OpenAI and Anthropic.

Massive Microsoft Service Outage

On November 12, 2026, a global outage affected key Microsoft 365 services, including Outlook email, the corporate messenger Teams, the SharePoint file-sharing platform and the Copilot artificial intelligence. The incident, which began in the United States and gradually spread to 'any region', resulted in the inability to access mailboxes, delays in message delivery and disruptions to video conferencing. According to the monitoring site Downdetector, the peak of complaints about Outlook problems reached nearly 140,000 reports from 74 countries, with the largest number of affected users in North and South America.

Causes and the Company's Response

Microsoft officially ruled out a cyberattack, explaining the incident by the fact that 'a large number of servers unexpectedly became unavailable', which created excessive load on the remaining infrastructure. The company clarified that the increased load was caused not by a rise in user traffic but by the loss of part of the servers, which forced engineers to redistribute connections between nodes for load balancing. Despite the measures taken, including halting deployments and restarting affected servers, Microsoft representatives admitted that recovery attempts were 'not producing the expected results', and that some previously restored services could become unavailable again.

Impact on Business and Adjacent Industries

The outage had a direct impact on the operations of other technology companies that use Microsoft's infrastructure. Artificial intelligence makers OpenAI and Anthropic reported problems connecting to Microsoft services, which left some tools non-functional. As a result of the disruptions, electric truck maker Workhorse Group was forced to postpone the publication of its third-quarter financial results from November 12 to November 16. Government agencies in Singapore and Australia also reported difficulties, and in the United Kingdom a number of medical practices switched to telephone communication with patients due to email being unavailable.

Current Status and Recommendations

As of the morning of November 13, recovery was proceeding unevenly: in North America, Teams operations were partially resumed, but users in other regions continued to face difficulties. Microsoft recommended that administrators monitor status through the Microsoft 365 admin center, and that regular users use Exchange cached mode in the desktop version of Outlook to work with already downloaded emails. Experts note that switching to a different client application will not solve the problem, since the outage affects the server side of Exchange Online, and for coordinating work during the downtime it is recommended to use alternative communication channels that do not depend on the Microsoft ecosystem.