Overview
- Reports of access failures to Exchange Online began around midday on Thursday, November 12, and user-monitoring site Downdetector showed early-afternoon peaks with more than 130,000 Outlook reports at the incident's high point.
- The outage started with Exchange Online (Outlook) in the Americas and expanded to affect Microsoft 365 components such as Teams, OneDrive, SharePoint, Copilot and Defender XDR across multiple regions.
- Microsoft said a portion of its distributed infrastructure saw an elevated load after an unexpected number of servers became unavailable, a condition that likely produced the connectivity errors.
- To reduce impact Microsoft opened incident records EX1550543 and MO1550821, redistributed connection traffic, paused deployments and restarted affected servers while posting updates in the Microsoft 365 admin center and its public status portal.
- Significant disruption persists for many users and organizations, there is no firm ETA for full restoration, and administrators are advised to follow the incident pages and status.cloud.microsoft for ongoing updates and guidance.