Microsoft 365 outage affects 130,000 users as engineers race to restore services

Microsoft is still working to restore services after a widespread outage disrupted access to Outlook, Teams, and other Microsoft 365 applications. The disruption affected nearly 130,000 users globally, according to reports collected by Downdetector. Microsoft now believes unavailable servers and problems with automated health checks contributed to the incident. The software giant has started bringing affected infrastructure back online. However, some users continued experiencing connectivity problems as recovery efforts progressed Thursday. Server failures caused disruption Microsoft traced the disruption to an infrastructure problem that left several servers unexpectedly unavailable. Those failures increased the workload on remaining servers, creating additional pressure across its infrastructure. The company said overall traffic had not increased enough to explain the elevated load. Instead, unavailable servers forced the remaining infrastructure to handle more requests than usual. We're actively restarting and validating the affected servers to return them to service. In parallel, we're assessing whether reverting a small number of recent configuration updates we identified could help accelerate recovery. More info under EX1550543 and MO1550821 in the…— Microsoft 365 Status (@MSFT365Status) November 12, 2026 An issue with automated server health checks may have contributed to the problem. These checks help Microsoft determine whether individual servers are functioning correctly. However, a failure in that process apparently prevented some servers from remaining available. The resulting connectivity problems affected several Microsoft 365 products. Users reported difficulties accessing Outlook mailboxes and sending or receiving emails. Others struggled to load Teams and Microsoft’s productivity applications. Downdetector recorded nearly 130,000 reports during the outage’s peak. Reports covered Word, Excel, PowerPoint, SharePoint and OneDrive. Microsoft’s Copilot assistant also experienced disruptions. Microsoft tests recovery measures Microsoft has begun validating an alternative health-check method to bring affected servers back online. The approach has already worked on a subset of impacted machines. The company is now expanding that fix across its affected infrastructure. It is also developing an automated process to identify unresponsive servers and restart them. Microsoft previously said it was restarting affected machines to restore availability. The company also paused deployments and configuration changes while investigating potential causes. Its investigation identified recent configuration updates as a possible contributor. Microsoft is now assessing whether reversing some of those changes could speed up recovery. In its latest update, Microsoft said it was actively restarting and validating affected servers. It also confirmed that engineers were evaluating whether reverting selected configuration updates would accelerate the process. The company has not confirmed that configuration changes directly caused the outage. Its investigation remains ongoing. Recovery remains underway Microsoft previously reported progress in restoring Teams services across North America. However, reports from affected users indicated that connectivity problems had not disappeared entirely. The disruption also exposed how failures within individual infrastructure components can affect several interconnected services. Microsoft’s cloud-based applications depend on extensive server infrastructure to handle authentication, communications, and data access. Automated health checks play an important role in maintaining that infrastructure. They help operators identify malfunctioning machines before those failures affect wider services. A problem with the checks themselves can complicate that process. Microsoft’s recovery efforts now involve restoring unavailable servers and examining recent infrastructure changes. The company has yet to provide a definitive explanation for the underlying failure. Users experiencing continued problems may still encounter intermittent access issues as Microsoft works through its recovery process. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Aamir is a seasoned tech journalist with experience at Exhibit Magazine, Republic World, and PR Newswire. With a deep love for all things tech and science, he has spent years decoding the latest innovations and exploring how they shape industries, lifestyles, and the future of humanity.