Microsoft 365 is the connective tissue of the modern enterprise. Securing it is no longer an email problem — it is identity, data, endpoint, and collaboration security as one continuous fabric.
The four pillars
Identity (Entra ID + Conditional Access), threat protection (Defender XDR), information protection (Purview), and posture management (Secure Score + Exposure Management). Each pillar is necessary; none is sufficient alone.
Patterns that hold up under audit
Phishing-resistant MFA for all admins, risk-based access for users, sensitivity labels enforced at the data layer, and automated investigation tuned to your industry baselines. Document the why, not just the what.
Microsoft 365Entra IDDefenderPurview