Microsoft 365 outage hits Outlook, Teams and Copilot worldwide

Update, 13 November 2026 (morning, Pakistan time): The outage was still not fixed more than 12 hours after it began. At 03:13 GMT on Friday, Microsoft said the changes it had applied to restore service were "not taking as expected" and that it was looking for other ways to add capacity. Microsoft has said it has no indication of a cyber-attack. Details are in the update section below; the original report from early on 13 November (Pakistan time) follows.

A widespread Microsoft 365 outage that began on Thursday, 12 November 2026, left many people around the world unable to open their Outlook inboxes, join Teams calls or reach files in SharePoint and OneDrive. Microsoft says the cause was not a surge in traffic but "a large number of servers being unexpectedly unavailable", which pushed extra load onto the rest of its infrastructure. By early on Friday, 13 November, the company said some servers were back in service, but recovery was still partial and some restored servers had become unresponsive again once traffic returned.

Microsoft first described the problem as affecting users in the Americas, then said people "in any region" could be affected, TechCrunch reported. Reports of problems with Outlook on the outage-tracking site Downdetector peaked at nearly 140,000 around 18:00 GMT on Thursday (11 pm in Pakistan), according to the BBC. The Associated Press put the Outlook peak at nearly 130,000 reports just after 1 p.m. US Eastern time. Downdetector figures are user-submitted reports, not a count of affected accounts, so the real number of people affected is not known.

Which Microsoft services were affected?

Microsoft's status notices listed Exchange Online (the service behind Outlook email for businesses), Microsoft Teams, SharePoint Online, Microsoft 365 Copilot and the Defender XDR security product as potentially affected, Engadget reported. Later in the afternoon US time, Planner, To Do, Intune, Defender for Office 365, Purview, Power BI and the Microsoft 365 Apps admin center were added to the list.

Consumers were affected as well as companies. TechCrunch reported that personal users could not reach OneDrive storage or Office on the web, and The Guardian said Downdetector reports also covered Word, Excel and PowerPoint. Microsoft's own admin center, where it normally posts detailed incident notes for IT departments, was itself hard to reach at times, so the company relied on its Microsoft 365 Status account on X for public updates. The incidents are tracked under the reference numbers EX1550543 and MO1550821.

The outage also spread to tools built on top of Microsoft's services. OpenAI said it was investigating broken Microsoft connectors in ChatGPT, and Anthropic said an upstream provider issue was affecting its Microsoft 365 connector for Claude, the BBC reported. Electric truck maker Workhorse Group postponed its third-quarter results from 12 to 16 November, citing disruption from the outage.

What does Microsoft say caused the outage?

Microsoft has not published a full root-cause report, and its explanation developed through the day. Its status updates on X give this sequence (times in GMT on 12 November unless noted):

• 18:48: Microsoft said it had begun "redistributing connection traffic across our broader worldwide infrastructure to help balance the load".
• 19:12: It said it had "paused all deployments", was moving traffic off the affected infrastructure and was restarting servers.
• 19:31: It said the elevated load "isn't driven by an increase in traffic, but by a number of servers being unexpectedly unavailable".
• 19:50 to 20:19: It said servers were failing automated health checks, the routine tests a system uses to decide whether a server should receive traffic. It said it had not found a recent change linked to the start of the problem, but the failures "may originate from a specific component that's responsible for processing server health".
• 21:00: An alternative health-check method let some servers return to service, and Microsoft said it was applying that more widely.
• 21:40: It said it was assessing whether reverting "a small number of recent configuration updates" could speed recovery.
• 22:09: It said its actions "have not provided the anticipated relief" and that "a core process on affected servers is becoming overwhelmed".
• 23:04: A portion of servers had been returned and "remain stable so far", with "limited recovery" seen.
• 00:06 on 13 November: "The servers we returned to service can become unresponsive again once they receive traffic," Microsoft said, adding that it was temporarily limiting which types of traffic could reach the affected systems.

In plain terms, Microsoft's account is that a growing share of its email and collaboration servers were wrongly marked as unhealthy or stopped responding, so the remaining servers had to carry more users than they were built for, and some of those then failed too. Mark Gregory, an associate professor of engineering at RMIT University in Australia, told The Guardian this kind of failure tends to become "a cascading problem": when part of a server pool is lost, "all of the users are trying to access the remaining servers, and that overloads them". His view that a network-layer misconfiguration was behind it is outside analysis; Microsoft has only said configuration updates are one possibility it is examining.

Was this a cyberattack?

Microsoft has not said anything to suggest an attack. Its public explanation points to server health checks, an overwhelmed internal process and possibly recent configuration changes. The Daily Context has not seen any evidence of malicious activity, and readers should treat claims of a hack as unverified unless Microsoft or investigators say otherwise.

Who is affected and what can users do?

The people most affected are organisations that run their email, chat and file storage on Microsoft 365, including businesses, schools and public bodies in many countries, as well as individuals with personal Outlook.com and OneDrive accounts. Because the problem sits on Microsoft's side, changing passwords or reinstalling apps will not fix it.

Microsoft has said customers may see a gradual recovery as users reconnect. Practical steps that follow from its guidance are limited: IT administrators can follow the two incident numbers in the Microsoft 365 admin center when it is reachable, or the public status page and the Microsoft 365 Status account on X when it is not. Messages sent during an email outage are often delivered later rather than lost, but Microsoft has not yet said whether any mail was lost in this incident, so anything time-critical may need confirming by another route.