How DMARC supports CMMC compliance & strengthens email security

The Cybersecurity Maturity Model Certification (CMMC) is a framework developed by the U.S. Department of Defense (DoD) and released in 2019. It aims to assess the cybersecurity practices of contractors and subcontractors handling Federal Contract Information (FCI) and Controlled Unclassified Information (CUI). Starting in 2025, organizations must meet CMMC compliance requirements to bid on certain DoD contracts.

The CMMC framework consists of three levels:

• Level 1: Basic safeguarding of FCI with self-assessments.
• Level 2: Focused on protecting CUI, aligning with the Nation Institute of Standards and Technology (NIST) SP 800-171 standards, and requiring self or external assessments.
• Level 3: Advanced cybersecurity practices to protect CUI against Advanced Persistent Threats (APTs), involving annual compliance verification from NIST.

Email security is critical to CMMC compliance, and implementing Domain-based Message Authentication, Reporting, and Conformance (DMARC), Sender Policy Framework (SPF), and DomainKeys Identified Mail (DKIM) is essential in protecting organizations from email-based attacks.

The role of DMARC in CMMC compliance

1. Strengthening email security

Email remains a primary attack point for cybercriminals targeting DoD contractors. Attackers frequently spoof domains and launch phishing attacks to trick users into providing credentials, sending funds, or providing unauthorized access.

By implementing DMARC, SPF, & DKIM, organizations can:

• Prevent email spoofing: Ensure that only authorized senders can use a certain domain.
• Block phishing attempts: Reduce the risk of phishing attacks targeting employees and supply chain partners.
• Enhance email authentication: Align with CMMC requirements for securing communication channels.

2. Meeting CMMC Level 2 & Level 3 requirements

CMMC Level 2 requires organizations to implement email security measures to safeguard CUI. Level 3 goes further by mandating advanced security controls, making DMARC enforcement important in achieving compliance.

How DMARC helps with CMMC compliance:

• Visibility & reporting: DMARC provides real-time visibility into unauthorized email activity.
• Policy enforcement: DMARC policies decide how organizations should handle unauthorized emails (monitoring, quarantining, or rejecting).
• Continuous monitoring: Organizations can monitor their email communication and adjust authentication settings to reduce APTs.

3. Avoiding compliance violations & breaches

Failing to implement email security measures can result in:

• Lost DoD contracts due to non-compliance with CMMC requirements.
• Increased risk of cyberthreats, making organizations more vulnerable.
• Reputational damage from data breaches caused by phishing or email spoofing.

Implementing DMARC, SPF, and DKIM reduces these risks while helping meet CMMC compliance requirements.

Strengthening CMMC compliance with DMARC

As the DoD enforces stricter cybersecurity standards, organizations must take proactive steps to secure their email communications. Implementing DMARC, SPF, and DKIM supports CMMC compliance, decreasing the risk of email-based threats and showing a commitment to securing CUI.

Is your organization ready to secure its email and achieve CMMC compliance? At Sendmarc, we provide advanced solutions to help defense contractors implement DMARC, SPF, and DKIM seamlessly. Contact us today to strengthen your business’s email security and compliance strategy.