What Is the DMARC pct Tag?

What is the DMARC pct Tag?

The DMARC pct tag defines the percentage of email messages that a domain owner wants to apply their DMARC policy to. It allows gradual enforcement of DMARC by testing policies on a subset of traffic before full deployment. The tag is expressed as a number from 0 to 100, representing the percentage of messages subject to the DMARC policy defined in the p= tag.

For example, if your DMARC record contains pct=50 and p=quarantine, then 50% of messages failing DMARC checks will be quarantined, while the other half will be delivered normally. This enables organizations to phase in enforcement safely without affecting legitimate mail flows.

How the DMARC pct Tag Works

A DMARC record example using the pct tag:

In this case, only 25% of unauthenticated messages are rejected, allowing administrators to monitor results and identify issues before moving to 100% enforcement.

When combined with aggregate reports, the pct tag helps domain owners measure how DMARC policies affect different mail streams and sending services.

Best Practices for Using DMARC pct

• Start with a low percentage (e.g., pct=10) when moving from p=none to enforcement
• Gradually increase to 100% as all legitimate sources align with SPF and DKIM
• Monitor reports closely to detect unauthorized senders or misconfigurations
• Use DMARC RUA reports for progress tracking

The pct tag applies only to messages that fail DMARC validation. It does not affect messages that pass SPF or DKIM alignment.

DMARC pct and DMARCeye

DMARCeye visualizes how the pct tag impacts enforcement across your domain’s mail flow. The platform tracks policy coverage, message outcomes, and compliance trends, helping you transition smoothly from “monitor” to “reject” without disrupting legitimate mail.

By correlating authentication failures and policy sampling, DMARCeye ensures that enforcement adjustments are data-driven and free of risk.

Sign up for a free trial of DMARCeye today and secure your email domain.

To learn more about DMARC and DMARC-related terms, explore the DMARCeye Glossary.