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Cloud Security & Administration Authority

Microsoft 365 Security Checklist for Nonprofits & Small Businesses

Essential security configurations every organization must verify to secure identities, eliminate tenant sprawl, and protect sensitive data.

Securing Your Organization’s Digital Core

For most growing organizations, Microsoft 365 is much more than an email provider—it is the central operating environment holding sensitive donor records, financial documents, client communications, and internal collaboration files.

Unfortunately, because Microsoft 365 is frequently set up quickly and left unmanaged, default security settings often leave organizations vulnerable to credential compromise, unauthorized access, and data leaks.

Common Microsoft 365 Security Misconceptions

Many organizations assume that because Microsoft operates the platform, security is automatically configured correctly. In reality, Microsoft provides the tools, but each organization remains responsible for how those tools are configured and managed.

Another common misconception is that purchasing higher licensing tiers automatically improves security. While certain plans unlock additional capabilities, unconfigured security features provide little protection if administrative controls are not properly implemented.

The Essential Microsoft 365 Security Checklist

Use this foundational checklist to review your organization’s tenant configuration:

• • Mandatory Multi-Factor Authentication (MFA): Enforce secure second-factor authentication for every user account across all devices to prevent 99% of password-based attacks.
• • Block Legacy Authentication: Disable older protocols (like POP/IMAP) that bypass modern security policies and MFA enforcement.
• • Conditional Access Policies: Configure rules to restrict sign-ins based on risk level, device compliance, or geographic location.
• • SharePoint Permission Audit: Review external sharing links, guest access privileges, and folder-level permissions to ensure internal data remains secure.
• • Active Offboarding Protocols: Establish strict administrative procedures to revoke licenses, disable accounts, and secure mailboxes immediately when staff depart.

How On-Target Computers Helps

We help organizations harden their cloud environments, eliminate tenant sprawl, and streamline administrative oversight. To see how we execute comprehensive administrative overhauls, review our Microsoft 365 Modernization Case Study.

Explore our core capabilities on our Microsoft 365 Services page, read our real-world outcomes in our Success Stories, or request an evaluation through our Free Website & Compliance Audit.

Ready to Secure Your Microsoft 365 Tenant?

Request a Free Website & Compliance Audit or schedule a consultation with On-Target Computers.