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What a Microsoft 365 Security Assessment Covers

A useful assessment explains how configuration and working practices affect risk. It should give your team a licence-aware improvement plan, rather than a list of settings to switch on without context.

Published 22 October 2026 · Content updated 29 October 2026
Published by CyberXpert

Define the question first

A tenant review can support different goals: reduce account compromise risk, review external sharing, prepare for assurance or check a recent migration. Agree the objective and scope before granting access. Record whether the work includes assessment only or hands-on implementation.

Identity and privileged access

The review should consider authentication methods, MFA coverage, privileged roles, guest access and relevant legacy authentication. Conditional Access may help control access where licensing supports it. Emergency access arrangements and user impact need to be considered before policy changes are made. See Microsoft’s security defaults guidance and Conditional Access overview for the different models and licence requirements; do not remove existing protections without a validated replacement.

Email and collaboration

Relevant areas include mail-flow protection, mailbox settings, external forwarding and domain-authentication configuration. Teams, SharePoint and OneDrive sharing deserve their own attention. The right settings depend on the organisation’s legitimate collaboration needs, not simply the strictest possible policy. Microsoft’s SharePoint and OneDrive external-sharing overview explains the tenant and site settings that need to be considered together.

If account compromise is suspected, use the guidance on responding to suspected email account compromise and the urgent incident contact route rather than waiting for a planned assessment.

Logging and response readiness

Ask which events are recorded, who can investigate and how long the relevant evidence is available. Available logs and retention depend on licensing and configuration. A recommendation to monitor an event is incomplete without a named owner and a route to act on suspicious activity. Use the Microsoft Purview auditing overview and audit-retention guidance to check the relevant licence, workload and policy. Do not assume one retention period covers all evidence.

Understand the licence boundary

Microsoft 365 subscriptions provide different capabilities. Defender for Business is one endpoint-security option for small and medium-sized organisations; its inclusion or availability does not mean every advanced security feature is licensed. The assessment should identify capability gaps before recommending additional subscriptions.

Make findings useful

Each material finding should describe the observed condition, affected scope, risk and practical recommendation. It should also identify dependencies, likely user impact and whether the recommendation can be delivered with current licences. Prioritisation should reflect the business rather than a score alone.

Implement in controlled stages

Pilot changes with representative users. Confirm recovery and rollback arrangements before altering authentication or collaboration controls. Update guidance for staff and support teams. A staged approach helps identify operational consequences before a policy affects everyone.

After an assessment, our guide to prioritising Microsoft 365 improvements can help organise a justified sequence of changes.

Decide what happens afterwards

An assessment is a point-in-time view. Agree whether your team will own remediation, whether CyberXpert will assist and when the changes will be checked. Ongoing monitoring and investigation require their own explicit service scope.