Anthropic, the AI company that owns Claude, reported that an upstream Microsoft 365 service incident caused elevated error rates and slow response times for Claude’s Microsoft 365 connector and Claude for Outlook on November 12, 2026.
In the Claud status page, they share that the disruption began with initially impacting requests to mail, SharePoint, Teams chat, and calendar tools, while preventing new connections to the connector from completing. Claude’s engineering team traced the issue to the upstream provider, which subsequently began restarting affected servers to restore functionality.
As of Anthropic’s latest update, mail, calendar, and search tools within the Microsoft 365 connector continue to fail for most requests, and Claude for Outlook remains disrupted, with some users unable to open the add-in or complete mail and calendar actions. Anthropic is monitoring Microsoft’s official status updates and will post further notices once full service is restored.
