Microsoft Outage Triggers Chaos Across Outlook, Teams and Copilot — Spills Over to OpenAI and Anthropic

Microsoft Corp. (NASDAQ:MSFT) continued working to restore services Thursday evening as a widespread Microsoft 365 outage disrupted Outlook, Teams, Copilot and other workplace applications for thousands of users, while also affecting Microsoft integrations used by OpenAI and Anthropic.

Microsoft Identifies Fault As Recovery Continues

Downdetector complaints for Outlook peaked at 138,058 around 1 pm ET before declining to roughly 34,490 that evening. By 5:47 p.m., Microsoft 365 complaints had fallen to nearly 13,000, while Teams drew 763 reports. The figures measure user submissions, not the total number of affected customers.

In Microsoft’s latest publicly accessible service-health update, issued at 8:45 pm ET Thursday, the company said restarting affected servers was producing "positive results," but engineers were monitoring stability before expanding fixes. It had not announced full restoration.

An earlier update identified an overwhelmed process responsible for secure connections that left servers unable to handle requests. Microsoft said it was testing a configuration adjustment, rolling back a recent network change and temporarily limiting traffic while gradually restoring capacity.

Outlook, Teams And Copilot Features Disrupted

Microsoft listed Exchange Online mailbox access and email delivery among the problems. Teams calendar and meeting scheduling, Copilot Chat and access to work data, Microsoft Graph requests and parts of SharePoint, Planner and Defender also faced disruption.

However, Microsoft said core Teams messaging and meetings remained largely functional, as did direct access to SharePoint files. The distinction matters because the outage impaired features across products rather than shutting down every service.

OpenAI, Anthropic And Workhorse Report Fallout

OpenAI said on its status page that new Microsoft connector connections could fail and tools might not work as expected. Anthropic also traced Microsoft 365 connector problems to an upstream provider, Reuters reported Thursday.

Reuters noted that electric truck maker Workhorse Group Inc. (NASDAQ:WKHS) postponed its third-quarter earnings announcement from Nov. 12 to Nov. 16, citing the global Microsoft outage. The disruption followed a separate Azure outage in October 2025 that also affected workplace services.

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