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Microsoft 365 Security Assessment and Security Best Practices

A Microsoft 365 security assessment is a structured review of how a tenant is configured and used, covering identity and access, email security, data protection, collaboration sharing, device access, logging and admin privileges, measured against recognized baselines and delivered as a prioritized remediation plan. Microsoft Secure Score gives a starting point, but an assessment adds context: which gaps actually matter for your users, data and regulators, and in what order to fix them.

This article explains what an Office 365 and Microsoft 365 security assessment covers and lists the security best practices most tenants are missing. RockTeam delivers assessments as part of our Microsoft 365 consulting services.

What a Microsoft 365 Security Assessment Covers

AreaWhat is reviewed
Identity and accessMFA coverage, conditional access policies, legacy authentication, guest accounts, risky sign-ins
Privileged accessGlobal admin count, role assignments, break-glass accounts, just in time access
Email securityAnti-phishing, anti-spam and malware policies, safe links and attachments, SPF, DKIM and DMARC, external forwarding rules
Data protectionSensitivity labels, data loss prevention, encryption, retention and legal hold
CollaborationSharePoint and OneDrive external sharing, anonymous links, Teams guest and external access
Devices and appsDevice compliance requirements, app consent and third-party application permissions
Logging and responseUnified audit logging, alert policies, retention of logs and incident response readiness
Licensing fitWhether current licenses include the security features you need

Baselines Used for Benchmarking

  • Microsoft Secure Score, Microsoft’s built-in measurement of security posture and recommended actions.
  • CIS Microsoft 365 Foundations Benchmark, widely used community consensus settings.
  • CISA SCuBA secure configuration baselines, published by CISA for Microsoft 365 and required for federal civilian agencies under Binding Operational Directive 25-01; useful guidance for any organization.

Microsoft 365 Security Best Practices

  1. Require MFA for everyone, with phishing-resistant methods for admins.
  2. Block legacy authentication protocols that bypass MFA.
  3. Use conditional access to require compliant devices or trusted locations for sensitive access.
  4. Keep global admins to a minimum and use least-privilege roles and separate admin accounts.
  5. Turn on SPF, DKIM and DMARC and move DMARC toward enforcement.
  6. Block automatic external forwarding of mail, a common sign of compromise.
  7. Restrict external sharing and anonymous links in SharePoint and OneDrive.
  8. Control app consent so users cannot grant third-party apps access to company data.
  9. Apply sensitivity labels and DLP to the data that matters most.
  10. Keep audit logging on and review alerts and risky sign-ins regularly.

How a Security Assessment Works

  1. Scope and access. Agree the workloads in scope and grant read-only admin access.
  2. Collect configuration. Export settings, policies, roles, Secure Score and sign-in data.
  3. Interview. Understand business needs, regulated data and existing risks.
  4. Analyze. Compare against baselines and rate each gap by risk and effort.
  5. Report. Deliver an executive summary and a prioritized remediation roadmap.
  6. Remediate and retest. Fix findings in planned phases, then re-measure.

Security Before Copilot and AI

Microsoft 365 Copilot can surface any content a user is permitted to see, so oversharing that was once hidden becomes visible. Tightening sharing, permissions and sensitivity labels is a core part of Copilot readiness and a natural follow-on to a security assessment. For ongoing oversight, a vCISO can own the security roadmap, and Microsoft 365 managed services can keep settings from drifting.

Want to know how secure your Microsoft 365 tenant really is?

RockTeam’s Microsoft 365 security assessment reviews identity, email, data, sharing and admin access against recognized baselines and gives you a prioritized plan to fix what matters. Start with a no cost consultation.

Explore Microsoft 365 Consulting

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Microsoft 365 Security Assessment FAQs

A structured review of a Microsoft 365 tenant’s identity, email security, data protection, sharing, device access, logging and admin privileges against recognized baselines, delivered with a prioritized remediation plan.

Secure Score is a useful starting point, but it does not weigh risks against your business, data and regulators. An assessment adds that context and a practical order of fixes.

Common references are Microsoft Secure Score, the CIS Microsoft 365 Foundations Benchmark and CISA’s SCuBA secure configuration baselines for Microsoft 365.

For most organizations, a few weeks from access to final report, depending on tenant size, workloads in scope and the number of stakeholders interviewed.

It is strongly recommended. Copilot can surface any content users can access, so fixing oversharing, permissions and labeling first reduces the risk of exposing sensitive data.