Why this matters
M365 is the operational nerve center for most growing companies — identity, mail, files, collaboration, all in one tenant. The default M365 configuration is permissive by design (Microsoft optimizes for ease-of-onboarding, not security). After 6–12 months of unmanaged use, almost every tenant accumulates the same set of preventable security issues: legacy authentication enabled, conditional access gaps, oversharing in SharePoint, MFA holes, audit logging not configured. 365 Security Reviews — Standard finds them, prioritizes them, and tracks remediation — quarterly, with monthly drift checks in between.