Microsoft 365 Outage Disrupted Outlook, Teams and Copilot
Microsoft confirmed ongoing degradation of Microsoft 365 services. The incident affected Exchange Online, Teams, SharePoint Online, Copilot and some security features.
The Microsoft 365 outage disrupted several enterprise cloud services, including Outlook and Exchange Online, Microsoft Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR. Microsoft confirmed service degradation on November 12, with the incident reportedly continuing on November 13.
The company said that parts of its infrastructure in several regions faced increased load. Servers subsequently failed automated health checks. Microsoft began restoring some servers, but recovery was gradual and limited. Some systems stopped responding again after returning to operation.
The Microsoft 365 outage affected communication and security tools
For organizations using Microsoft 365, the incident could mean limited access to email, team communications, documents and service administration. Connections to Exchange Online and other services within the platform were affected.
The Associated Press noted that Downdetector recorded a peak of nearly 130,000 problem reports for Outlook. However, this figure does not represent the number of directly affected users or the precise scope of the outage across individual organizations.
From a cybersecurity perspective, the reported restriction of the Safe Links feature in Microsoft Defender for Office 365 is also relevant. Safe Links is used to check web links in emails and other services. However, available information does not suggest that this was a cyberattack or confirmed exploitation of a vulnerability.
The cause has not yet been finalized
Microsoft has not yet disclosed the final cause of the incident or a timetable for fully restoring all services. The company described a connection between increased infrastructure load and failed automated health checks, but it has not definitively confirmed whether the problem was triggered by a specific recent change to a configuration or component.
The scope of the impact may vary by country, individual tenant and service used. This means that not all customers necessarily experienced the same restrictions, and some functions may have recovered faster than others.
What to watch next
Administrators should monitor service status in Microsoft Service Health, where Microsoft publishes ongoing information about degradation and recovery. Confirmation of full recovery for Exchange Online, Teams, Copilot and Defender security services will be particularly important.
A final incident analysis and information about corrective measures are also expected. At present, there is no official confirmation linking the Microsoft 365 outage to a security attack.
Sources
- Microsoft Service Health Status – Microsoft publicly reports Microsoft 365 degradation and the ongoing incident.
- University of Pennsylvania – Microsoft Incident Reports for PennO365 – Mirrors incidents EX1550543 and MO1550821, the scope of affected services and ongoing information about server recovery.
- Associated Press – Independently confirms widespread user impacts affecting Outlook, Teams and Copilot and reports Microsoft’s statements about failed health checks.
Verified and updated: November 13, 2026 06:23
