Microsoft 365 Outage Lasts Over 6 Hours; Outlook, Teams and Other Services Still Not Restored

TechFlow reported that on November 13, Microsoft 365 services began experiencing a large-scale outage around 1:54 a.m. Beijing Time today. Initially, users in the Americas were unable to access Exchange Online mailboxes; Microsoft later confirmed that users in any region worldwide could be affected.

According to Microsoft's service status page, affected services include Outlook.com, OneDrive, OneNote, To Do, Teams and the web version of Microsoft 365. Other Microsoft 365 services may also experience issues. As of publication, the outage has persisted for over 6 hours, and the status remains "Service Degradation".

Microsoft said the outage was not caused by a traffic surge, but by a large number of servers unexpectedly becoming unresponsive, causing the remaining infrastructure to become overloaded. A core process on affected servers became overloaded, resulting in capacity loss. Microsoft has paused all deployments, restarted affected servers and rerouted traffic to other routes.

In its latest update, Microsoft said servers that had been restored may become unresponsive again after resuming traffic. It is currently analyzing diagnostic data to identify the cause, while restricting the types of traffic allowed to access affected infrastructure in some regions and rebuilding some servers with previous configurations to verify effectiveness. Microsoft expects to publish its next update before 12:30 p.m. Beijing Time.

Source: TechFlow