DMARC Record Generator & Analyzer

Understanding DMARC Tags

A DMARC record is composed of semicolon-separated key/value pairs called tags. Some tags are required, while others provide additional reporting and policy controls.

How to Use This Tool

1. Select the Generate Record tab.
2. Choose your preferred DMARC policy.
3. Configure optional settings such as alignment, reporting addresses, and policy percentage.
4. Generate the TXT record.
5. Copy the generated record and publish it under _dmarc.yourdomain.com.
6. Use the Analyzer tab to verify your record before deployment.
7. Use the DNS Lookup tab to confirm the published record matches your configuration.

Worked Example

Suppose your company wants to monitor email authentication before enforcing DMARC.

v=DMARC1;
p=none;
rua=mailto:dmarc@example.com;
adkim=r;
aspf=r;
pct=100
        

This policy tells receiving mail servers to take no action on failing messages, but to send aggregate reports to dmarc@example.com. After reviewing reports and confirming all legitimate mail sources authenticate correctly, the policy can gradually be changed to quarantine and eventually reject.

DMARC Deployment Best Practices

• Start with p=none to monitor authentication without affecting mail delivery.
• Review aggregate reports regularly to identify legitimate senders.
• Ensure SPF and DKIM are correctly configured before enabling enforcement.
• Move gradually from none to quarantine, then finally to reject.
• Use relaxed alignment unless strict alignment is specifically required.
• Always publish only one DMARC TXT record per domain.
• Keep reporting email addresses active so you continue receiving reports.
• Test configuration changes using the built-in analyzer before publishing.

Common DMARC Configuration Errors

Invalid Policy Value

The p tag only accepts none, quarantine, or reject. Any other value results in an invalid record.

Duplicate Tags

Each DMARC tag should appear only once. Duplicate entries may cause mail receivers to ignore later values or produce unexpected behavior.

Missing Version Tag

Every DMARC record must begin with v=DMARC1. Without this required tag, the record is invalid.

Unsupported or Unknown Tags

Custom or misspelled tags are ignored by most receivers and indicate a configuration mistake. Remove unknown tags to keep your record standards compliant.

Incorrect Reporting Address

Reporting addresses should use the correct mailto: format. Invalid email addresses prevent reports from being delivered successfully.

Publishing Multiple DMARC Records

A domain should publish only one DMARC TXT record. Multiple records can lead to inconsistent interpretation by mail providers.

Why Validate Your DMARC Record?

Small syntax mistakes can prevent a DMARC policy from functioning correctly. Validation checks every tag, detects formatting errors, duplicate parameters, unsupported values, and missing required fields before the record is published. This reduces deployment errors and helps ensure receiving mail servers interpret your policy exactly as intended.

The integrated DNS lookup also allows you to compare the published record with your local configuration, making troubleshooting significantly easier after DNS changes have propagated.

Conclusion

A properly configured DMARC policy strengthens email security by preventing domain spoofing, improving message authentication, and providing visibility into how your domain is being used across the internet. Whether you are deploying DMARC for the first time or maintaining an existing policy, creating an error-free record is essential.

This DMARC Record Generator & Analyzer simplifies the entire process by allowing you to generate standards-compliant records, validate existing configurations, perform live DNS lookups, and understand every DMARC tag through clear explanations. By following recommended deployment practices and gradually progressing from p=none to quarantine and finally reject, you can confidently protect your domain while maintaining reliable email delivery.