Microsoft has published extensive guidance on securing external sharing in SharePoint Online, but it's spread across multiple documentation portals, admin centers, and compliance guides. In this guide, we have consolidated Microsoft's official best practices into one actionable resource to help you implement an enterprise-grade security strategy.
1. Layered External Sharing (Tenant → Site → File)
Microsoft recommends a layered approach to external sharing configuration.
2. Using Microsoft Purview for Data Loss Prevention (DLP)
Microsoft Purview provides robust Data Loss Prevention (DLP) capabilities.