The Top 10 M365 Security Best Practices for MSPs

Table of Contents

As an MSP, securing your clients’ M365 environments is one of the most critical aspects of your service offering. With cyber threats on the rise, proactive security measures are essential to keep client data safe and build trust. Here are the top M365 security best practices to help you enhance protection, ensure compliance, and stay ahead of emerging threats.

1. Enforce Multi-Factor Authentication (MFA)

Multi-Factor Authentication is one of the most effective and straightforward ways to protect user accounts. A study from Cornell University found that enforcing MFA can prevent up to 99% of account compromise attacks. Set it up as a baseline security requirement for all users, regardless of their access level, and regularly audit MFA usage to ensure ongoing compliance.

2. Implement Conditional Access Policies

Conditional Access Policies provide an additional layer of control by requiring specific conditions to be met before granting access. This may include device compliance, geographic location, or user risk. Set up policies that enforce location-based restrictions and block access from risky locations or unknown devices.

  • Best Practice: Develop specific policies for high-risk scenarios, like requiring MFA for logins from outside the client’s typical region, to provide targeted security where it’s needed most.

3. Secure Email with Anti-Phishing and Anti-Spam Protections

Phishing remains one of the most prevalent and dangerous threats in M365 environments. Use Microsoft Defender for Office 365 to activate anti-phishing, anti-spam, and anti-malware protections. Configure these tools to identify and block high-risk emails, minimizing the chance of a successful phishing attack.

  • Advanced Security Tip: Use Safe Links and Safe Attachments policies to protect users from harmful links or attachments, even in real-time. Ensure these settings are tuned to minimize false positives while maximizing threat detection.

4. Regularly Review User Access and Permissions

Access creep, where users retain access to resources they no longer need, can create security risks. Regularly review and audit user permissions to ensure only authorized individuals have access to sensitive information.

  • Recommendation: Set up a quarterly or bi-annual permissions review process to check access levels across all M365 services, including SharePoint, Teams, and OneDrive.

5. Enable Data Loss Prevention (DLP) Policies

Data Loss Prevention policies can help you monitor and protect sensitive information from accidental or intentional leakage. In M365, DLP policies can identify, monitor, and protect sensitive data (e.g., financial records, health information) by restricting sharing or alerting administrators to potential data breaches.

  • Pro Tip: Customize DLP policies to meet client-specific compliance requirements and ensure that sensitive data stays secure. Use auditing tools to monitor DLP actions and refine policies as needed.

6. Set Up Secure Mobile Device Management (MDM)

Many users access M365 from personal and mobile devices, which can introduce security vulnerabilities. Use Intune, Microsoft’s Mobile Device Management solution, to enforce policies that require encryption, passcodes, and other protections on any device that accesses M365 resources.

  • Best Practice: Encourage clients to use Mobile Application Management (MAM) policies, which protect M365 data on mobile devices without affecting personal data, offering a balanced approach to security.

7. Utilize Microsoft Secure Score for Ongoing Security Improvements

Microsoft Secure Score is a dynamic report within M365 that provides a security rating based on the configurations and practices across M365 services. Use this tool as a benchmarking and tracking resource to understand your security posture and identify areas of improvement.

  • Pro Tip: Regularly monitor Secure Score and implement recommended actions to strengthen security while keeping track of changes over time.

8. Conduct Regular Security Awareness Training

User awareness is a key component of a robust security strategy. Equip your clients’ employees with knowledge about phishing, ransomware, and other cyber threats through regular security training. Make sure users understand the role they play in protecting their accounts and sensitive data.

  • Advanced Tip: Consider simulating phishing attacks and tracking the results to assess the effectiveness of your training and identify users who may need additional guidance.

9. Enable Auditing and Alerting for Suspicious Activity

Proactively monitoring your M365 environment for suspicious activities, such as failed login attempts or unusual file access patterns, can help detect potential security incidents early. Configure alerting and logging for key security events and review audit logs to track abnormal behavior.

  • Suggestion: Set up alerts for high-risk activities, like administrative changes or large data downloads, to catch potential breaches as they occur. Learn more about how Augmentt’s Alerts work.

10. Regularly Update and Patch M365 Apps

Ensure that all M365 apps are updated regularly to receive the latest security patches. Microsoft frequently releases updates that address vulnerabilities in its apps, so keeping client environments current minimizes the risk of known threats.

  • Automate Updates: Where possible, automate the update process to reduce the risk of vulnerabilities caused by outdated software.

Be Proactive to Stay Secure

MSPs play a crucial role in securing clients’ Microsoft 365 environments, and by implementing these best practices, you can significantly reduce security risks. The best security strategy is one that’s consistently applied and regularly reviewed, so make sure to revisit these steps and adjust as threats evolve.

Start enhancing your clients’ M365 security today with these proactive strategies—and see why so many MSPs trust award-winning solutions like Augmentt to help them safeguard their clients’ environments with confidence.

Author
Gavin Garbutt
Co-Founder & Chairman of Augmentt

FAQ

Using our GDAP tool & Magic Link, setting up is easy! You can integrate with your CSP partner portal in minutes
Augmentt uses a combination of Microsoft Secure Score best practices as well as industry standards such as NIST & CIS. You can use the out of box templates to get started right away and even build your own custom templates to match your client requirements.
Out of box, Augmentt comes pre-configured to not be noisy. Very few Microsoft alerts are critical in nature so you will be receiving tickets for account breaches and not minor user log related events. That said, everything is customizable and you can turn alerts on & off to match your clients’ needs.
No. You can choose to schedule alerts to any stakeholder you want and at the frequency you want or manually download reports when you need them.
Regardless of how MFA is managed across your tenants, we have you covered. Augmentt supports Conditional Access Policies, Security Defaults, Entra ID per user (Legacy) MFA as well as 3rd party MFA services like DUO.
No. You can use Augmentt to monitor and manage all clients regardless of their licensing. For environments with no premium licensing you can still provide alerts and monitoring for account breaches and configure security best practices. For environments with premium licensing, you can leverage Microsoft’s premium alerts and premium security configurations such as Conditional Access Policies.
Augmentt is one of the few vendors SOC 2 Type II, and GDPR compliant.
Site licenses to make sure you can deliver standardized service across all clients very affordably.

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