5 Microsoft 365 Security Settings Every Business Should Enable

Microsoft 365 is one of the most widely used cloud platforms for email, collaboration, and file storage. But many businesses don't realize that the default security settings are not enough to protect against today's cyber threats.

With phishing attacks, credential theft, and account takeovers on the rise, enabling the right security features is critical.

To help you strengthen your organization's defenses, here are the five essential Microsoft 365 security settings every business should enable.

1. Multi-Factor Authentication (MFA)

The most important security setting in Microsoft 365.

MFA adds an extra layer of protection by requiring users to verify their identity using a second factor, such as an authenticator app or hardware security key. Prefer phishing-resistant methods, such as passkeys or FIDO2 security keys, where supported.

Why it matters:

• Protects accounts even if passwords are stolen
• Reduces the risk of account compromise from stolen passwords
• Supports access control and authentication requirements

If your business hasn't enabled MFA for all users yet, this should be your first priority.

2. Conditional Access Policies

Control who can access your data based on location, device, or risk level.

Conditional Access allows you to create rules that automatically block or restrict access based on specific conditions, for example, preventing sign-ins from outside trusted countries or requiring MFA when risk is high.

Key benefits:

• Block suspicious sign-in attempts
• Enforce secure access for remote workers
• Allow access only from approved devices or locations

Conditional Access requires Microsoft Entra ID P1, which is included in Microsoft 365 Business Premium. Policies based on user or sign-in risk require Microsoft Entra ID P2.

3. Microsoft Defender for Office 365

Advanced protection against phishing, ransomware, and malicious files.

Defender for Office 365 provides real-time scanning of emails, attachments, and links. It helps prevent users from opening harmful content or being tricked by phishing attempts.

Why businesses need it:

• Stops malicious links with Safe Links
• Scans attachments using Safe Attachments
• Detects impersonation and spoofing attacks
• Provides threat investigation and reporting

Safe Links and Safe Attachments require Microsoft Defender for Office 365 Plan 1 or Plan 2. Plan 1 is included in Microsoft 365 Business Premium.

4. Identity Protection & Risk-Based Alerts

Detect unusual or suspicious activity before it becomes a breach.

Microsoft Entra ID Protection detects identity risks such as leaked credentials, password spray attacks, and unfamiliar sign-in properties. Full risk reports, risk policies, and user-risk alerts require Microsoft Entra ID P2.

What it does:

• Automatically flags risky sign-in attempts
• Blocks or challenges risky sign-ins through configured Conditional Access policies
• Alerts your admin when user risk reaches the configured threshold

These automated protections help you catch attacks early, often before users even notice.

5. Data Loss Prevention (DLP) Policies

Prevent sensitive information from leaving your organization.

DLP allows you to identify and protect confidential data such as financial records, personal information, customer data, or intellectual property.

How it helps:

• Detects when users try to share sensitive files externally
• Blocks accidental or intentional data leaks
• Enforces configured rules for handling sensitive information

DLP coverage depends on your licenses and the locations included in your policies. Microsoft 365 Business Premium includes DLP for Exchange Online, SharePoint Online, and OneDrive.