Microsoft Defender for Cloud Apps

Microsoft Defender for Cloud Apps is the most operationally efficient CASB for Microsoft 365 customers. Included in M365 E5 licensing at no additional cost, requiring zero MX record changes or proxy configuration, and natively integrated with Conditional Access, Entra ID, Intune, and Purview, it delivers a complete CASB capability within the Microsoft security architecture that no third-party vendor can replicate at equivalent integration depth.

The limitation is equally clear. The value is almost entirely within the Microsoft ecosystem. Third-party SaaS app connector quality is inconsistent, API inspection depth for non-Microsoft applications is less than Netskope, and organisations whose SaaS estate extends significantly beyond M365 will find gaps.

The verdict: Microsoft Defender for Cloud Apps is right for Microsoft 365 enterprises wanting CASB bundled into existing M365 E5 licensing without adding a separate vendor. Organisations with significant non-Microsoft SaaS estates should evaluate Netskope or Zscaler.

Last reviewed: May 2026

Strongest: Policy enforcement

Watch out for: Cloud analytics

Best for

Microsoft 365 enterprises wanting CASB bundled into M365 E5 without adding a separate vendor.

Not suitable for: Multi-cloud environments where Google Workspace or non-Microsoft SaaS dominates.