The DMARC Enforcement Lifecycle: From ‘None’ to ‘Reject’ in 5 Steps

Taking into consideration the rising number of phishing and spoofing attacks nowadays, securing domains has become crucial. Implementing DMARC (Domain-based Message Authentication, Reporting, and Conformance) is the key part of the process. Moving your DMARC policy from ‘None’ to ‘Reject’ requires a careful, step-by-step approach to ensure your legitimate emails are delivered smoothly. This guide outlines the DMARC enforcement steps, transitioning your policy from ‘None’ to ‘Reject’ smoothly and effectively.

Step 1: Start with a DMARC Record in ‘None’ Mode

 

The first step is to publish a DMARC record with the ‘None’ policy (p=none). This initial phase is for monitoring only—no emails will be blocked. Instead, you’ll receive DMARC aggregate reports that reveal how your domain is being used. Key actions at this stage include:

• Create a DMARC record with the p=none policy.
• Ensure that your SPF and DKIM records are properly configured.
• Set up a mailbox to receive DMARC reports for analysis.

 

A simple DMARC record with a “none” policy can look like this:

v=DMARC1; p=quarantine; adkim=s; aspf=s;

 

Step 2: Review and Analyze DMARC Reports

 

Once the DMARC record is live, it’s time to dive into the reports. These reports provide insight into:

• The sources sending emails on your behalf.
• Whether SPF and DKIM are properly aligned for each source.
• Any unauthorized use or potential abuse of your domain.

 

Analyzing DMARC reports can be challenging, as aggregate reports are typically in XML format and failure reports in JSON. Use a DMARC reporting tool to simplify this process, making it easier to identify and address issues.

Here are some popular DMARC reporting tools that can help make the analysis a lot easier:

 

1. EasyDMARC – Provides user-friendly dashboards, comprehensive aggregate report analysis, and forensic report insights.
2. DMARCian – Offers tools to analyze and visualize DMARC data with a focus on improving email security.
3. Valimail Monitor – A free tool for monitoring DMARC compliance and understanding your email ecosystem.

 

Step 3: DMARC enforcement to ‘Quarantine’ Policy

 

After identifying legitimate email sources and properly configuring your domain’s SPF and DKIM for them, you’re ready to implement a ‘Quarantine’ policy (p=quarantine). This tells receiving servers that emails sent out via your domain and fail DMARC checks should be sent to spam or junk folders instead of the inbox. To implement this step:

 

• Update your DMARC record to p=quarantine.
• Gradually apply the policy by using the pct tag to define the percentage of emails affected (e.g., pct=25).
• Monitor reports closely to ensure legitimate emails are not mistakenly flagged.

 

Step 4: Resolve Alignment Issues

 

During the ‘Quarantine’ phase, you may discover legitimate emails that fail DMARC checks due to alignment problems. Common causes include:

 

• Third-party services sending emails without proper SPF or DKIM setup.
• Misconfigured email systems within your organization.

 

You will need to adjust SPF, DKIM, or other settings as necessary to bring everything into compliance.

 

Step 5: Moving to DMARC ‘Reject’ Policy

 

The final step in this lifecycle is implementing a ‘Reject’ policy (p=reject). This ensures unauthorized emails are blocked outright, providing the highest level of protection for your domain. To complete this step:

 

• Confirm that all legitimate email sources are aligned with SPF and DKIM.
• Update your DMARC record to p=reject.
• Continue to monitor DMARC reports to catch new issues or unauthorized activity.

 

 

Moving from ‘None’ to ‘Reject’ is a careful process that requires attention and ongoing monitoring. By following these DMARC enforcement steps, you’ll strengthen your domain’s email security while ensuring legitimate emails get through. While a ‘Reject’ policy offers the strongest protection for your domain, it’s important to remember that this is just one of the crucial steps. Ongoing monitoring of reports and adjusting your domain’s settings as needed is key to maintaining long-term security. DMARC enforcement not only protects your brand but also helps make the email ecosystem safer for everyone.

Use the DMARC record checker tool to lookup your domain’s DMARC record.