Microsoft 365 Outage Disrupts Outlook and Teams for Tens of Thousands of Users
Outlook outage reports peaked near 130,000 on Thursday as Microsoft worked to restart servers hit by an overloaded core process, and tens of thousands of users still reported problems into the evening.
A widespread Microsoft outage disrupted Outlook, Microsoft 365 and other services for tens of thousands of users across the United States on Thursday, with problems lasting into the evening as the company worked to bring servers back online.
Reports of problems with Outlook peaked at 128,874 at 1:09 p.m. ET, according to outage tracker Downdetector. Reports for Microsoft 365 passed 47,000 around 1:20 p.m. ET. By about 9 p.m. ET, more than 28,000 users were still reporting issues with Outlook and more than 9,000 with Microsoft 365.
Microsoft points to an overloaded process
Microsoft said a core process on affected servers was becoming overwhelmed and causing a loss of capacity. The company said it was restarting and checking servers to return them to service, moving traffic to other routes and limiting some types of traffic to the affected servers. In an update shortly before 9 p.m. ET, Microsoft said it was seeing positive results from the restarts and was watching the servers to confirm they stayed stable.
The company’s service health page said users could be unable to connect to Outlook, Teams, SharePoint, Copilot, Defender, To Do and Purview. Microsoft also warned that restored servers “can become unresponsive again once they receive traffic.”
The outage reached other AI services
The disruption also affected connectors used by OpenAI and Anthropic to power their artificial intelligence services, USA Today reported. OpenAI said it was looking into an issue with Microsoft connectors, and Anthropic said it had found an issue with an upstream provider affecting its Microsoft 365 connector.
The outage followed a disruption last month involving Microsoft’s Azure cloud platform, which affected the company’s productivity software and services in a range of industries worldwide.
Reporting based on coverage by USA Today, with contributions from Reuters.
