Domain-based Message Authentication, Reporting and Conformance (DMARC) is an email authentication protocol that helps protect your domain from spoofing, phishing and unauthorised email use.
DMARC works by building on Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). It tells receiving mail servers what to do if an email fails one or both of those checks. Domain owners can set a policy to monitor messages, quarantine suspicious emails or reject them entirely. This gives you control over how your domain is treated when authentication fails.
A key benefit of DMARC is visibility. When configured correctly, it provides reports showing who is sending email on behalf of your domain and whether those messages pass authentication. This makes it easier to spot misconfigurations, abuse or attempted impersonation.
DMARC has become increasingly important as mailbox providers tighten their filtering rules. Without it, even legitimate emails can lose trust over time, especially for marketing campaigns or high-volume sends. A strong DMARC policy improves inbox placement, protects your brand and reassures recipients that emails from your domain are genuine.
Example: A business sets a DMARC policy of "quarantine". Emails claiming to be from its domain that fail SPF and DKIM are automatically diverted to spam, reducing the risk of phishing reaching users' inboxes.
DMARC is most effective when combined with a clear email strategy — explore our Email Marketing services to ensure your campaigns are both trusted and deliverable.