Massive Microsoft 365 outage disrupts Outlook, Teams, Copilot worldwide
Microsoft is investigating a widespread outage affecting multiple Microsoft 365 services, including Outlook, Microsoft Teams, and Copilot, as users report connectivity problems worldwide.
Microsoft is investigating a widespread outage affecting multiple Microsoft 365 services, including Outlook, Microsoft Teams, and Copilot, as users report connectivity problems worldwide.
BleepingComputer has received numerous reports from users experiencing problems accessing Microsoft's services, including complaints that Outlook is down.
According to Downdetector, which tracks user-submitted outage reports, complaints surged Thursday afternoon across numerous Microsoft services, including Outlook, Microsoft 365, Teams, Copilot, Azure, OneDrive, and the Microsoft Store.
In a Microsoft 365 admin center advisory tracked as MO1550821, Microsoft confirmed that customers may be unable to connect to multiple services, including Exchange Online, Microsoft Teams, SharePoint Online, Microsoft 365 Copilot, and Microsoft Defender XDR.
The company says the Microsoft 365 incident began Thursday at 1:26 PM ET, although it began investigating reports of Exchange Online mailbox connectivity problems in the Americas earlier in the day.
While the company initially reported Exchange Online connectivity problems in the Americas, it later confirmed that users in any region could be affected.
Microsoft initially attributed the disruption to elevated infrastructure load across multiple regions, but has determined that the problem was caused by servers unexpectedly becoming unavailable.
We determined the elevated load isn't driven by an increase in traffic, but by a number of servers being unexpectedly unavailable; straining the remaining infrastructure.
The company says it has paused all deployments, redistributed connection traffic across its worldwide infrastructure, and is moving further traffic away from affected systems to reduce load.
Microsoft is also restarting affected servers to restore capacity and return services to normal operation.
Microsoft has not yet responded to BleepingComputer's questions about the root cause of the outage and whether it is related to Thursday's earlier Teams disruption.
We're working to safely return them to service, Microsoft said in an update on X; bleepingComputer contacted Microsoft with questions about the outage and will update our story if we receive a response.
Update 11/12/26 6:57 PM ET: Microsoft says it is seeing limited recovery from the widespread Microsoft 365 outage after successfully returning some affected servers to service.
Microsoft also said it was investigating whether reverting a small number of recent configuration updates could accelerate recovery.
What happened
Microsoft is investigating a widespread outage affecting multiple Microsoft 365 services, including Outlook, Microsoft Teams, and Copilot, as users report connectivity problems worldwide.
BleepingComputer has received numerous reports from users experiencing problems accessing Microsoft's services, including complaints that Outlook is down.
According to Downdetector, which tracks user-submitted outage reports, complaints surged Thursday afternoon across numerous Microsoft services, including Outlook, Microsoft 365, Teams, Copilot, Azure, OneDrive, and the Microsoft Store.
What changed
In a Microsoft 365 admin center advisory tracked as MO1550821, Microsoft confirmed that customers may be unable to connect to multiple services, including Exchange Online, Microsoft Teams, SharePoint Online, Microsoft 365 Copilot, and Microsoft Defender XDR.
The company says the Microsoft 365 incident began Thursday at 1:26 PM ET, although it began investigating reports of Exchange Online mailbox connectivity problems in the Americas earlier in the day.
While the company initially reported Exchange Online connectivity problems in the Americas, it later confirmed that users in any region could be affected.
Who is affected
Microsoft initially attributed the disruption to elevated infrastructure load across multiple regions, but has determined that the problem was caused by servers unexpectedly becoming unavailable.
We determined the elevated load isn't driven by an increase in traffic, but by a number of servers being unexpectedly unavailable; straining the remaining infrastructure.
Why it matters
The company says it has paused all deployments, redistributed connection traffic across its worldwide infrastructure, and is moving further traffic away from affected systems to reduce load.
Microsoft is also restarting affected servers to restore capacity and return services to normal operation.
Technical details
Microsoft has not yet responded to BleepingComputer's questions about the root cause of the outage and whether it is related to Thursday's earlier Teams disruption.
Response
We're working to safely return them to service, Microsoft said in an update on X; bleepingComputer contacted Microsoft with questions about the outage and will update our story if we receive a response.
What security teams should do
Update 11/12/26 6:57 PM ET: Microsoft says it is seeing limited recovery from the widespread Microsoft 365 outage after successfully returning some affected servers to service.
What to watch next
Watch for revised vendor guidance, fixed versions and mitigation updates.