Microsoft is still working through a global Microsoft 365 outage that has lasted more than 10 hours. The disruption began on November 12, 2026, with Exchange Online mailbox access failures in the Americas, and it spread to Outlook, Teams, SharePoint, Copilot, and Microsoft Defender XDR users in any region.
The company has not yet found a fix that holds. Servers that engineers return to service keep becoming unresponsive again once traffic reaches them, and Microsoft says it has no estimated time for full restoration.
Recovery steps and incident tracking
Microsoft says it is running several workstreams at the same time to address the current blocker and bring parts of its infrastructure back to a healthy state. The incidents are tracked as EX1550543 and MO1550821 in the Microsoft 365 admin center. If the admin center is unavailable, Microsoft has also pointed administrators to an alternative status update link.
The company has moved to three fallback measures as restarts continue to fail. It is temporarily limiting some traffic types to the affected infrastructure in certain locations, rebuilding a subset of affected servers on a previous configuration, and adjusting traffic protocols while redistributing load and applying what Microsoft calls strategic traffic blocking. Microsoft says it sees partial recovery in regions where those measures are in place, but it also says that recovery is not stable and users may still see intermittent failures.
Microsoft has also said it is recovering impacted infrastructure in an isolated manner and watching performance closely before expanding restoration more broadly. It expects service availability to improve gradually as the restoration process spreads across the affected infrastructure.
What Microsoft found so far
Microsoft first blamed elevated load across several regions, then corrected that explanation. Traffic had not increased, but a number of servers had unexpectedly dropped out, which strained the rest of the infrastructure.
The servers were failing automated health checks, which determine whether a machine can take requests. Engineers paused all deployments, shifted traffic to other parts of the worldwide infrastructure, and restarted affected servers, but those steps did not restore service. Microsoft later said its actions had not provided the anticipated relief and found that a core process on the servers was being overwhelmed.
An alternative health check method brought some servers back, and they appeared stable at first. Microsoft’s latest updates say that stability did not hold once traffic returned. The rebuild on a previous configuration is the clearest sign so far that Microsoft suspects a recent change, although it has not confirmed one as the cause.
Impact across services and regions
Downdetector recorded more than 120,000 Outlook problem reports at the peak, and those reports came from 74 countries. Report volumes have fallen since partial recovery began. Microsoft’s service health page lists Exchange Online, Teams, SharePoint Online, Microsoft 365 Copilot, Defender, Planner, To Do, Intune, Purview, and Power BI among the affected services.
Features that do not depend on Exchange Online reportedly continued working. The disruption also reached other companies: OpenAI and Anthropic both reported problems with their Microsoft 365 connectors, and electric truck maker Workhorse Group postponed its third-quarter results to November 16.
Microsoft says the outage is not the result of a cyberattack. Executive Vice President Charles Lamanna confirmed it was not caused by a security breach, according to Business Standard. Microsoft also said it is not aware of any malicious activity causing the outage.
Guidance for administrators
Microsoft says the fault is in its own infrastructure, so local troubleshooting will not restore service. Administrators are told to track MO1550821 and EX1550543 in the Microsoft 365 admin center, or use status.cloud.microsoft if the admin center will not load.
Microsoft also advises against resetting passwords, rebuilding Outlook profiles, or changing tenant settings in response to the errors. Even in regions showing recovery, some access may remain intermittent because Microsoft is deliberately blocking some traffic types. The company says administrators should warn users about phishing emails and fake support calls that exploit the outage, and they should plan for delayed mail delivery once service returns and queued messages are processed.
Microsoft says it is evaluating traffic throttling, protocol adjustments, and failover routing to increase frontend server capacity and improve stability. It is also expanding testing in a controlled environment to improve traffic monitoring and issue detection. Recovery remains a priority, and Microsoft plans to publish a post-incident report with the root cause and additional safeguards once the disruption is mitigated.
Recent recovery updates
Microsoft says it has made further progress in restoring affected Microsoft 365 services. It says actions have been completed across portions of the impacted infrastructure and user traffic has been gradually restored, with improvements in mailbox access and delayed email processing.
Some users may still experience intermittent disruptions while recovery continues. Engineers are now working on the remaining affected infrastructure, reducing queued emails and delivery backlogs, and increasing server capacity to keep performance consistent. Microsoft has also kept an extended 48-hour email timeout window in place so delayed messages do not expire while email processing catches up. Full service restoration has not yet been confirmed, and further updates remain under incident ID MO1550821.
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