Anthropic shipped write tools for the Microsoft 365 connector on July 7, 2026, and left them switched off for every organization that had connected before that date. Nothing in the product says so. Here is how to check in ten seconds, the two admin gates in two different consoles, the scope that deserves a second look, and the write path already running in your building that will derail the diagnosis.
Claude Desktop's Microsoft 365 connector reads email body but not attachments. Three workarounds exist. Two are blocked in most secure tenants by design. The path that lasts is registering your own Entra ID app with Mail.Read delegated. Here is the architecture, the failure modes, and the PowerShell that runs.
When AI indexes your files, SharePoint and OneDrive expose data very differently. Here is how permission models, governance gaps, and the oversharing problem change everything about where you store documents for AI workflows.
Your SharePoint and OneDrive setup is organized for people browsing folders. Claude reads metadata. That mismatch is why the M365 Connector finds nothing useful and Cowork struggles with your files. Restructuring for AI access takes a weekend and pays off immediately.