Microsoft has restored its services following a major global outage that disrupted Outlook, Microsoft 365, Teams, Copilot and several other applications for more than 24 hours, affecting businesses, government agencies and millions of users across multiple countries.
The disruption began on November 12 and initially affected thousands of users in the United States before spreading across other regions. Users reported difficulties accessing email accounts, sending and receiving messages, managing calendars and connecting to workplace applications.
The incident also affected integrations used by artificial intelligence platforms, including OpenAI and Anthropic, which rely on Microsoft 365 services to connect with users’ accounts.
Outlook Reports Crossed 138,000 in the United States
According to outage-tracking platform Downdetector, reports of Outlook problems peaked at approximately 138,058 in the United States around 1 p.m. Eastern Time on November 12.
At 2:07 p.m. ET, more than 97,000 Outlook-related incidents had been reported, alongside over 38,000 reports involving Microsoft 365 and approximately 4,500 reports concerning Teams.
The disruption subsequently spread internationally, with users in Asia-Pacific, Europe and other regions reporting connectivity problems. The outage affected organisations across more than 70 countries and territories, highlighting the widespread dependence on Microsoft’s cloud-based productivity services.
Unexpected Server Failures Behind the Disruption
Microsoft initially pointed to elevated workloads across several regions as it investigated the outage. However, the company later determined that increased traffic was not the underlying cause.
The investigation identified a number of servers that had unexpectedly become unavailable, placing additional pressure on the remaining infrastructure.
Microsoft said it was working to safely restore the affected servers and improve service capacity. Its recovery measures included pausing deployments, redistributing network traffic, moving additional connections away from affected infrastructure and restarting unavailable servers.
The company also reported challenges during the recovery process, as some restored servers became unresponsive again under traffic pressure.
OpenAI and Anthropic Integrations Also Affected
The disruption extended beyond Microsoft’s own applications to third-party services that depend on Microsoft 365 connectivity.
OpenAI reported problems with its Microsoft connectors, warning that new connections could fail and certain tools might not function as expected.
Anthropic also identified an issue with its Microsoft 365 connector linked to an upstream service provider.
The disruption demonstrated how problems within a major cloud platform can affect other technology companies and services that depend on its infrastructure.
Businesses and Government Agencies Face Operational Disruptions
The outage affected organisations across several sectors, including government, healthcare, financial services, aviation and education.
Some businesses experienced interruptions in internal communication, while financial firms and other organisations had to rely on alternative communication methods to maintain operations.
Government agencies in countries including the United States, Japan and Australia also reported disruptions. In some locations, organisations turned to telephone calls, paper-based processes and other backup arrangements when email and online systems became unavailable.
The incident highlighted the operational risks associated with relying heavily on a single technology provider for essential communication and business functions.
Microsoft Confirms Service Restoration
After more than a day of disruption, Microsoft confirmed that its services had fully recovered.
The company attributed the incident to server-related problems affecting services connected to Exchange Online and said it had found no evidence of malicious activity.
The restoration followed several rounds of technical adjustments and efforts to bring affected infrastructure back online.
The outage was Microsoft’s second major disruption involving its 365 services in 2026, renewing concerns about the reliability of widely used cloud platforms and the potential consequences of service interruptions for businesses and public institutions.
The incident has also reinforced the importance of backup communication systems, infrastructure resilience and contingency planning as organisations become increasingly dependent on cloud-based applications.
Disclaimer: This report has been editorially prepared using publicly available information and official company statements. Readers are advised to refer to official service announcements for further details.
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