What does a low DMARC success rate, nxdomain, and random subdomains mean and how can I fix it?

Email marketer from URIports shares that DMARC reports can be difficult to interpret, but are essential for understanding email authentication issues. Services exist to help parse these reports into something easier to understand.

Email marketer from Email Marketing Forum shares that random subdomains being used for spam may also indicate someone trying to phish your customers. You should report it to the Anti-Phishing Working Group.

Email marketer from EasyDMARC shares that implementing DMARC with a 'p=reject' policy is the most effective way to prevent domain spoofing and mitigate the impact of malicious emails using your domain or subdomains.

Marketer from Email Geeks suggests if you are confident that you have authenticated all legitimate mail from subdomains (if relevant), you could put an sp=reject tag in your DMARC record that would reduce this random subdomain abuse.

Email marketer from Postmark explains that it is important to start with a 'p=none' policy to monitor your email traffic before moving to a stricter policy like 'p=reject' to avoid accidentally blocking legitimate emails.

Email marketer from Reddit suggests that random subdomains in DMARC reports are often used by spammers to bypass DMARC policies. They recommend implementing a strict DMARC policy (p=reject) and monitoring reports for unauthorized use.

Email marketer from SparkPost recommends verifying SPF records to include all authorized sending IP addresses and ensuring DKIM signatures are correctly implemented and aligned with the 'From' domain to fix DMARC failures.

Email marketer from StackExchange answers that to resolve NXDOMAIN issues, ensure your DNS settings are correct and that your domain is properly configured. Regularly check and update your DNS records to prevent these errors.

Email marketer from Mailjet explains that a low DMARC success rate indicates that a significant portion of your emails are not passing DMARC authentication, potentially due to SPF or DKIM failures. This can damage your sender reputation and lead to deliverability issues.

Expert from Spam Resource explains that NXDOMAIN issues often arise when a sending server attempts to resolve a domain name that doesn't exist or is temporarily unavailable. This can be caused by DNS server problems, misconfigured DNS records, or the domain being recently registered or expired. Resolving this involves checking DNS configurations, ensuring proper DNS server setup, and allowing sufficient time for DNS propagation after changes.

Expert from Word to the Wise (Laura Atkins) emphasizes that setting up DMARC involves publishing a DMARC record in DNS and continually monitoring the reports to identify and correct authentication issues. Implementing a policy too quickly (such as p=reject) can result in lost mail, so it's crucial to start with a policy of 'p=none' and gradually increase the stringency as you gain confidence in your setup.

Expert from Email Geeks explains that nxdomain means the sending IP address has no reverse DNS.

Expert from Email Geeks explains that all the DMARC failure means is that someone, other than you, used your domain in email and since it is randomly generated subdomain it was probably used for a regular spam run using a from address generated at random from a list of harvested addresses.

Expert from Email Geeks shares that the main value of DMARC reporting is to identify mail you're sending that's not authenticated properly and paying too much attention to the background noise of random garbage mail in them isn't worth the effort.

Documentation from Dmarcian explains that 'nxdomain' in a DMARC report typically means that the domain used in the sending server's hostname does not exist. This often indicates a misconfigured or illegitimate sending source.

Documentation from Google explains that a DMARC failure means that a message failed DMARC authentication. This happens when the message doesn't pass SPF or DKIM checks, or the results of those checks don't align with the domain in the 'From' address.

Documentation from RFC Editor indicates that DMARC (Domain-based Message Authentication, Reporting, and Conformance) is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. It does this by defining policies that determine how recipient email servers should handle messages that fail authentication checks (SPF and DKIM).

Documentation from AuthSMTP states that NXDOMAIN errors in DMARC reports can stem from misconfigured SPF records, outdated DNS entries, or routing loops within email servers. Employing tools like `dig` or `nslookup` to diagnose these problems is beneficial, and they emphasize the need for consistently updated DNS records.

Documentation from Microsoft shares that to improve DMARC success rate, ensure that all your sending sources are properly authenticated with SPF and DKIM. Regularly review DMARC reports to identify and address any authentication issues.