Microsoft 365 Security Essentials: Settings Every Organization Should Review

Microsoft 365 is the backbone of daily work for many organizations — email, Teams, SharePoint, OneDrive, and identity all live in one place. It also includes strong built-in security features, but many are not enabled or tuned by default. A periodic Microsoft 365 security review helps make sure your configuration matches your risk tolerance.

Identity Comes First

Most Microsoft 365 security starts with Microsoft Entra ID (formerly Azure AD).

Require MFA for all users, using Security Defaults or Conditional Access policies.
Block legacy authentication protocols that can't support MFA.
Limit Global Administrators to a small number of dedicated accounts, and consider just-in-time access for privileged roles where licensing allows.
Review guest and external users regularly and remove access that is no longer needed.

Use Microsoft Secure Score as a Guide

Microsoft Secure Score provides a prioritized list of recommended improvement actions for your tenant. It's a useful starting point for discussion, not a finish line — some recommendations may not fit your business, and the score should be reviewed in context.

Email Protection

Publish SPF, DKIM, and DMARC records to make it harder for attackers to spoof your domain.
Review anti-phishing and safe attachment/link policies available with your licensing.
Consider disabling automatic external forwarding, a common technique for quietly exfiltrating mail from a compromised mailbox.

Data Sharing and Collaboration

Review SharePoint and OneDrive external sharing defaults. "Anyone" links are convenient but can expose data unintentionally.
Apply sensitivity labels to classify and protect confidential information where appropriate.
Set clear Teams guest access rules.

Devices and Access

If staff use personal or unmanaged devices, consider Conditional Access rules that require compliant devices for sensitive data, or limit access to the web versions of applications.

Logging and Retention

Confirm that unified audit logging is enabled and that log retention meets your business and regulatory needs. Make sure someone on your team (or a trusted partner) knows how to review audit logs if a question arises.

Backups

Microsoft's retention features are not the same as an independent backup. Evaluate whether a third-party Microsoft 365 backup solution fits your recovery requirements.

Make It a Recurring Review

Microsoft 365 changes frequently, and so does your organization. A quarterly or semi-annual configuration review keeps settings aligned with best practices as new features and staff changes arrive.

Need a second set of eyes? Push2Tek provides Microsoft 365 implementation, administration, and security review consulting. Schedule a Consultation.

This article is provided for general informational purposes and does not constitute legal, compliance, or audit advice. Every organization's environment and obligations are different.