DMARC Checker

A DMARC record is a TXT record in your DNS settings with the name _dmarc and a value like:

This tells receiving servers how to treat unauthorized mail, where to send reports, and how strictly to enforce alignment checks.

Think of them as layers of email security that work together:

• SPF (Sender Policy Framework): Checks whether an email was sent from a server or IP address authorized by the domain owner.
• DKIM (DomainKeys Identified Mail): Adds a cryptographic signature to each email, allowing the receiver to verify that the message hasn't been altered and truly comes from the claimed domain.
• DMARC: Ties them together by telling receiving mail servers what to do when these checks fail and sends you reports about authentication attempts.

You need all three working together for complete email protection.

Start with p=none to monitor without blocking anything. This lets you receive reports showing which email sources are passing or failing authentication, helping you spot any legitimate senders that aren't properly configured.

After reviewing reports for a week or two, switch to p=quarantine to send suspicious emails to spam folders. Once you're confident all legitimate sources are authenticated correctly, move to p=reject for maximum protection. This gradual approach prevents accidentally blocking your own legitimate emails.