REDMOND, Washington — Microsoft is continuing efforts to restore its cloud-based services after a widespread outage disrupted Outlook email, Microsoft Teams and several other Microsoft 365 applications, with the disruption extending into Friday, November 13, and affecting users and organisations across multiple regions.
The disruption began on Thursday, November 12, and affected access to Exchange Online, the cloud platform that powers Outlook email and calendars. Customers reported difficulties opening inboxes, sending and receiving messages, and connecting through web browsers, desktop applications and mobile devices. Other services reported as affected included Teams, SharePoint Online, Microsoft 365 Copilot and parts of Microsoft’s security and productivity platforms.
The scale of the disruption was reflected in outage-tracking reports. Downdetector recorded more than 130,000 reports of Outlook problems in the United States at the height of the incident, while reports came from dozens of countries and territories. Reuters reported that complaints were recorded in 74 countries and territories within about an hour, underlining the international reach of Microsoft’s cloud infrastructure.
Microsoft initially attributed the connectivity problems to elevated load across parts of its infrastructure in multiple regions. The company later clarified that the pressure was not simply the result of an unexpected surge in customer traffic. A number of servers had become unavailable, shifting demand onto the remaining infrastructure and contributing to a cycle of instability.
In updates shared with customers, Microsoft said affected servers were failing automated health checks and that a core process responsible for handling requests was becoming overwhelmed. Some servers that engineers had restarted initially appeared healthy but became unresponsive again after traffic was returned to them. The company therefore began testing alternative recovery methods, redistributing traffic and applying protective traffic-management measures.
Partial Recovery, But Services Not Fully Restored
By Friday morning, Microsoft said it was seeing improved server stability and capacity after applying a patch to an upstream authentication and routing configuration component. The company began expanding the changes across infrastructure supporting regions that were already within, or approaching, peak business hours.
However, the company cautioned that the recovery process was continuing and that it would keep monitoring the changes while developing additional modifications. Its incident notices continued to list problems affecting Exchange Online and multiple Microsoft 365 services. That means reports of partial improvement should not be interpreted as confirmation that every affected customer has regained normal access.
Microsoft also said it was not aware of malicious activity causing the incident. The company has said it will provide fuller details, including the root cause and measures intended to prevent a repeat, in a post-incident report after the disruption has been mitigated. The precise technical trigger therefore remains subject to Microsoft’s investigation.
Businesses And Public Services Feel The Impact
The outage reached beyond personal email accounts. Organisations that rely on Microsoft 365 for internal communications, scheduling, document collaboration and customer support faced interruptions as services became difficult to access. Reuters reported effects on government agencies in Australia, Japan and the United States, while businesses in parts of Asia also experienced operational problems.
Airlines IndiGo and Air India reported email-related support difficulties, although their flights were not affected, according to the Associated Press. Some banking and business communications in Hong Kong were also disrupted. The incident illustrated how a failure in a widely used cloud platform can affect organisations whose daily operations depend on connected services, even when their own local systems remain operational.
The disruption also extended to third-party technology services that connect to Microsoft 365. OpenAI reported problems with Microsoft connectors, including difficulties establishing new connections and tools not working as expected. Anthropic also identified an upstream provider issue affecting its Microsoft 365 connector. These effects demonstrate how cloud outages can spread beyond the company operating the infrastructure to other services that depend on it.
Why The Outage Matters
For businesses, government departments, schools and individuals, email is often a critical part of daily operations. When a cloud-based email platform becomes unavailable, users may lose access not only to messages but also to calendars, shared workflows, automated notifications and applications connected to their accounts. Even a gradual recovery can leave organisations dealing with delayed communication and backlogs after services return.
The incident also raises questions about resilience and concentration in cloud computing. Microsoft 365 is embedded in the operations of organisations around the world. While large cloud providers operate extensive infrastructure designed to distribute workloads, this outage shows that server and configuration problems can still create widespread disruption when interconnected services depend on the same underlying systems.
It is not yet possible to draw firm conclusions about the long-term implications before Microsoft publishes its technical review. The company has not identified a cyberattack as the cause, and the available incident updates point to infrastructure instability and server-capacity problems. Any comparison with previous major technology outages should therefore be treated cautiously until the investigation is complete.
What Users Can Do
Users experiencing problems should check Microsoft’s official Microsoft 365 service health and status page for the latest regional updates. Organisations with administrator access can also consult the Microsoft 365 admin centre for incident notices specific to their tenants. Repeatedly changing account settings or deleting profiles is unlikely to resolve a provider-side outage and could create additional problems.
Where business continuity is essential, organisations may need to use established alternative communication channels while waiting for full restoration. They should also verify whether delayed messages have been delivered before resending sensitive or time-critical information, to avoid duplicate communications.
As of Friday, Microsoft was reporting progress in stabilising affected infrastructure and gradually expanding its recovery measures, but the company had not declared the incident fully resolved in the latest updates reviewed for this report. Customers should continue to monitor official service notices for confirmation that Outlook and the wider Microsoft 365 ecosystem have returned to normal operation.
Sources: Reuters; Associated Press; Microsoft 365 Service Status; Microsoft incident notices reproduced by the University of Pennsylvania; The Guardian; Computerworld.