The Role of DMARC in Protecting Your Clients' Brand Reputation

What is DMARC?

DMARC (Domain-based Message Authentication, Reporting & Conformance) is an email authentication protocol that protects domains from unauthorized use — commonly known as email spoofing.

Why DMARC Matters

Brand Protection Without DMARC, anyone can send emails that appear to come from your client's domain. This enables:

• Phishing attacks targeting their customers
• Business email compromise (BEC) scams
• Brand reputation damage

Deliverability Major email providers (Google, Microsoft) are increasingly requiring DMARC for reliable delivery.

The Three DMARC Policies

1. None (p=none) — Monitor only, no enforcement
2. Quarantine (p=quarantine) — Suspicious emails go to spam
3. Reject (p=reject) — Unauthorized emails are blocked entirely

Implementation Roadmap

1. Start with monitoring — Deploy DMARC with p=none to see who's sending email as your client
2. Review reports — Identify legitimate senders that need to be authorized
3. Configure SPF and DKIM — Ensure all legitimate email sources are properly authenticated
4. Move to enforcement — Gradually tighten policy to quarantine, then reject

MSP Opportunity

DMARC implementation and monitoring is a valuable, recurring service. ThreatMate includes DMARC monitoring as part of our attack surface management platform.