Microsoft 365 outage disrupts Claude connector's email, calendar, and search

According to IT Home on November 13, 2026, Microsoft 365 experienced a service outage that disrupted Exchange Online, Outlook, SharePoint, and portions of Teams for nearly a day and a half, described in the report as one of the most severe service failures of recent years. Earlier that day, a Microsoft executive apologized for the disruption, expressed regret over the situation, and essentially acknowledged that the problem could not be resolved quickly.

While Microsoft's services were affected, Anthropic published successive updates on the Claude Status page, attributing faults in some of its own services to the Microsoft 365 connector. The first notice said Anthropic was investigating elevated error rates and sluggish responses on the Microsoft 365 connector, and warned that requests to access mail, SharePoint, Teams chat, and calendars through the connector could fail, while new users might be unable to complete the connection. A follow-up notice stated that the cause had been identified: an upstream service provider, whose problems were affecting the Microsoft 365 connector. Most requests for mail, calendar, and search functions were not being processed correctly, and new connections could also fail. Anthropic said it was in contact with the service provider. The latest update indicated that Anthropic was still working with the upstream provider to address the outage, and that most requests for mail, calendar, and search through the Microsoft 365 connector remained unable to be processed normally, which is where the incident stands at present.