Microsoft 365 Security Assessment: 9 Critical Settings Every Business Should Review

Microsoft 365 has become essential to how businesses communicate, collaborate, and manage information. From Outlook and Teams to SharePoint and OneDrive, these applications support daily operations across organizations of every size.

However, using Microsoft 365 does not automatically mean your business is taking full advantage of its security capabilities.

Misconfigured permissions, weak authentication policies, excessive administrative access, and overlooked security settings can leave sensitive business information exposed.

A Microsoft 365 security assessment helps identify these weaknesses before they become serious problems. By regularly evaluating your environment, your organization can strengthen cybersecurity, improve access controls, and make better use of the security tools already available through Microsoft.

Here are nine critical settings every business should review.

What Is a Microsoft 365 Security Assessment?

A Microsoft 365 security assessment is a structured evaluation of the security configurations, user permissions, authentication policies, and data protection controls within an organization's Microsoft environment.

The goal is to identify potential vulnerabilities, determine whether existing protections meet business requirements, and develop recommendations for improvement.

An assessment typically examines Microsoft Entra ID, Exchange Online, SharePoint, OneDrive, Teams, and other connected services.

Businesses that lack internal Microsoft security expertise can benefit from professional IT audits and assessments that help uncover configuration weaknesses and prioritize security improvements.

9 Critical Microsoft 365 Security Settings to Review

1. Multifactor Authentication (MFA)

Multifactor authentication adds another layer of protection beyond a username and password.

Even when an attacker obtains an employee's password, properly implemented MFA can make unauthorized access significantly more difficult.

During a Microsoft 365 security assessment, businesses should verify that MFA requirements cover all users, especially administrators and accounts accessing sensitive information.

Organizations should also review their authentication methods and consider phishing-resistant options where appropriate.

Simply enabling MFA is not enough. Businesses need to confirm that authentication policies are consistently enforced.

2. Conditional Access Policies

Conditional Access allows organizations to control access to Microsoft resources based on factors such as user identity, device compliance, location, and sign-in risk.

For example, a company might require additional authentication when employees access business applications from unfamiliar devices.

A security assessment should determine whether Conditional Access policies reflect the organization's actual working environment.

Businesses should review policy exclusions, emergency access accounts, and potential gaps that allow users to bypass intended protections.

Properly configured Conditional Access can help balance strong security with convenient access for authorized employees.

3. Administrative Privileges

Administrative accounts have elevated permissions that can affect users, applications, security policies, and organizational data.

When too many employees have administrative access, the consequences of a compromised account can become significantly more serious.

Businesses should regularly review which users have administrative roles and whether those permissions are necessary.

Applying the principle of least privilege helps ensure employees receive only the access required for their responsibilities.

Administrative access should also be reviewed whenever employees change positions or leave the organization.

4. Legacy Authentication

Some older applications and authentication methods do not support modern security protections.

Although Microsoft has retired many legacy authentication capabilities, businesses should still evaluate remaining applications, integrations, and authentication configurations.

An assessment should identify unsupported connections, outdated applications, and exceptions that may weaken access security.

Where possible, organizations should replace outdated authentication methods with supported, modern alternatives.

This review is particularly important for businesses operating older software alongside newer Microsoft cloud services.

5. Email Security and Phishing Protection

Email remains a common entry point for cyberattacks.

Microsoft 365 includes security capabilities that can help identify suspicious messages, malicious attachments, impersonation attempts, and potentially dangerous links.

However, available protections depend on licensing and configuration.

Businesses should evaluate anti-phishing policies, spam filtering, attachment protection, and email authentication settings such as SPF, DKIM, and DMARC.

A comprehensive cybersecurity strategy should also address employee awareness, since technical controls alone cannot eliminate every email-based threat.

6. SharePoint and OneDrive Sharing Permissions

SharePoint and OneDrive make collaboration easier, but improper sharing settings can expose confidential documents.

Employees may unintentionally create publicly accessible links or share sensitive files with unauthorized external users.

A Microsoft 365 security assessment should review organization-wide sharing policies, individual site permissions, external access, and existing sharing links.

Businesses should determine whether employees can share information outside the organization and what restrictions apply.

The objective is not to eliminate collaboration. It is to make sure information remains accessible to the right people without creating unnecessary exposure.

7. Device Security and Compliance

Employees frequently access Microsoft 365 through laptops, smartphones, tablets, and personal devices.

Each connected device can introduce security risks if it lacks appropriate protections.

Organizations should evaluate device management policies, operating system updates, encryption requirements, and endpoint protection.

Microsoft Intune and related tools can help enforce device compliance policies when properly licensed and configured.

Businesses should also consider how unmanaged devices access company information.

As discussed in Micro-Tech's guide to IT support for growing businesses, expanding technology environments require more structured management to maintain security and reliability.

8. Audit Logging and Security Monitoring

Security controls are more effective when organizations can identify suspicious activity and investigate potential incidents.

Microsoft 365 provides audit logging and monitoring capabilities that can help track administrative changes, file activity, user actions, and security events.

Businesses should confirm that appropriate logging is enabled and that retention settings support their operational and compliance requirements.

They should also determine who reviews alerts and how suspicious activity is investigated.

Collecting security information without a process for reviewing it can leave important warning signs unnoticed.

9. Data Loss Prevention Policies

Data loss prevention (DLP) policies help organizations identify and protect sensitive information.

Depending on available Microsoft 365 licensing, businesses can configure policies that detect information such as financial records, personal identifiers, and other confidential data.

A security assessment should determine whether DLP policies are appropriate for the organization's information and regulatory requirements.

Businesses should also review how policies affect email, SharePoint, OneDrive, and other supported applications.

Effective data protection requires understanding where sensitive information is stored, who can access it, and how it can be shared.

How Often Should Businesses Conduct a Microsoft 365 Security Assessment?

Microsoft 365 security should not be treated as a one-time configuration project.

New employees, additional applications, changing permissions, software updates, and evolving security threats can all affect an organization's security posture.

A comprehensive assessment at least annually is a reasonable starting point, with more frequent reviews for higher-risk environments.

Businesses should also consider additional assessments after major migrations, security incidents, significant organizational changes, or the introduction of new Microsoft services.

Regular evaluations help organizations identify configuration drift and maintain protections as their technology needs evolve.

Strengthen Your Microsoft 365 Security With Micro-Tech U.S.A.

Microsoft 365 provides powerful business capabilities, but maintaining a secure environment requires ongoing attention to configurations, permissions, devices, and user activity.

A Microsoft 365 security assessment helps businesses understand where their protections are effective and where improvements may be necessary.

Micro-Tech U.S.A. supports organizations through Microsoft solutions, cybersecurity services, managed IT support, and technology assessments designed to strengthen business IT environments.

Whether your organization needs help evaluating existing security settings, managing Microsoft applications, or developing a more comprehensive IT strategy, experienced technical guidance can make security improvements easier to prioritize and maintain.

Contact Micro-Tech U.S.A. to discuss your Microsoft 365 environment and learn how a proactive approach to IT security can help protect your business.