Decoding DMARC Reports: Key Metrics To Watch For Better Email Security


As the risks associated with phishing, spoofing, and various harmful email practices continue to grow, companies must establish systems that restrict email usage of their domain to verified senders only. DMARC (Domain-based Message Authentication, Reporting & Conformance) serves as one such system. Gaining insights from DMARC reports is crucial for enhancing email security and minimizing the likelihood of cyber threats.

This article will explain DMARC reports and emphasize the essential metrics to monitor for enhanced email security.


What is DMARC?


DMARC is a protocol designed for email authentication that enables domain owners to safeguard their domains against unauthorized usage. It operates alongside two other email verification technologies: SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail), ensuring that emails dispatched from a domain are genuine. 

After configuring DMARC, domain administrators gain access to comprehensive reports that update them on the effectiveness of email authentication and any possible risks aimed at their domain. 



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Key Metrics to Watch in DMARC Reports


1. Policy Alignment

DMARC ensures that the From address, which is visible to the recipient, matches the authentication methods of SPF and DKIM.

  • SPF Alignment: Verifies that the domain specified in the From email address corresponds with the domain listed in the SPF record. 

  • DKIM Alignment: Checks that the domain utilized in the DKIM signature is consistent with the domain found in the From email address.

As you examine your DMARC reports, pay attention to the alignment section to ensure that both SPF and DKIM are aligned with your domain. Any misalignments may suggest problems with your email configuration or the possibility of unauthorized senders.


2. Pass and Fail Rates

  • Pass Rate: A strong pass rate signifies that genuine emails are being successfully verified, enhancing both the reputation and security of your domain. 

  • Fail Rate: Conversely, a high fail rate may suggest that unauthorized individuals are attempting to impersonate your domain. It could also point to potential misconfigurations within your SPF or DKIM settings.

Aim to enhance the pass rate and lower the fail rate. Check the report for the SPF and DKIM tags to monitor these statistics.


3. Volume of Emails and Sources

DMARC reports offer important insights regarding the amount of emails dispatched from your domain and the originating IP addresses. For instance, an unexpected increase in email traffic or the appearance of unfamiliar or dubious IP addresses trying to send messages from your domain may signal potential security risks.

Examining the source IP section of the report allows you to pinpoint unauthorized senders. You can then block these senders or modify your SPF record to list only those sources you have authorized, which will strengthen the email security of your domain.


4. DMARC Policy Enforcement

A key aspect of DMARC reports is the enforcement of your DMARC policy. With DMARC, you can establish guidelines for mail servers regarding the treatment of emails that fail authentication.

  • None: Keep an eye on email traffic without taking any measures. 

  • Quarantine: Emails not passed the authentication are directed to the spam folder. 

  • Reject: Emails that do not meet authentication standards are outright rejected.

Reviewing the policy section in your reports allows you to assess if your policy is functioning correctly and if unauthenticated emails are being managed properly.



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5. Percentage of Messages Affected

The DMARC report you receive includes details about the proportion of emails influenced by your policy. If a significant percentage of messages are impacted, it may suggest that there are extensive misconfigurations in your SPF or DKIM settings. Check for fields labeled pct or percentage to determine the volume of messages affected by your DMARC policy. You may want to modify your policy to minimize any impact on legitimate emails.


Interpreting DMARC Reports for Better Security


Below are several suggestions for bolstering email security informed by insights from DMARC reports:

  • Address Authentication Issues: Should you notice a significant failure rate for SPF or DKIM, delve into the reasons behind it and adjust your DNS settings accordingly. This may involve incorporating additional authorized IP addresses into your SPF record. 

  • Strengthen Your DMARC Policy: If you're currently utilizing the None policy, think about transitioning to Quarantine or Reject once you are assured that your email authentication systems are operating effectively. 

  • Keep an Eye Out for Unusual Activity: Consistently track the number of emails dispatched from your domain and their origins. If you encounter unknown IP addresses or notice a sudden spike in email traffic, investigate right away to thwart potential phishing or spoofing threats. Read our guide.