Microsoft’s outage also cuts off Claude’s access to work email

When work email stops loading, asking an AI assistant to retrieve it may fail too. Anthropic says the Microsoft 365 incident is causing most requests through Claude’s Microsoft mail, calendar and search tools to fail. Claude for Outlook is also affected.

Microsoft’s 04:11 UTC update on November 13 still listed service degradation. Problems include mailbox access, delayed delivery and Copilot access to work data. Microsoft was investigating traffic imbalances after earlier changes failed to deliver the expected improvement.

A connector is the bridge between an assistant and another service. Anthropic began investigating at 17:52 UTC on November 12 and subsequently linked the problem to Microsoft’s incident. For people delegating office tasks to AI, a responsive assistant does not guarantee access to the documents or appointments it needs.

There are useful limits: Microsoft says most core Teams calls, meetings and chats still work, as does direct SharePoint file access. Before rerunning an automated workflow, check which email or calendar actions already completed. Microsoft has not published a final root cause, and its status page is continuing to change.

Source times: Microsoft status update, November 13, 2026, 12:11:46 Beijing / November 12, 11:11:46 PM EST; Anthropic initial notice, November 13, 01:52 Beijing / November 12, 12:52 PM EST; cited update, November 13, 06:23 Beijing / November 12, 5:23 PM EST.