DMARC (Domain-based Message Authentication, Reporting, and Conformance) is a way of checking that an email really was sent by the domain it claims to be from and hasn’t been tampered with on the way. But how does it work? Let’s break it down.

How DMARC Works

  1. Setting up DMARC: The owner of the domain (let’s call them the Domain Owner) sets up DMARC by creating an SPF (Sender Policy Framework) policy and a DKIM (DomainKeys Identified Mail) signature. They then publish these, along with a DMARC policy, in their DNS (Domain Name System) database.
  2. Sending an email: When someone (the Author) sends an email from the Domain Owner’s domain, the email goes through the Domain Owner’s mail submission service. This service adds the DKIM signature to the email and then sends it on its way.
  3. Receiving an email: When the email arrives at its destination (the Recipient), the Recipient’s mail service checks the SPF policy and the DKIM signature. It does this by looking up the necessary data in the Domain Owner’s DNS data.
  4. Checking DMARC: The results of the SPF and DKIM checks are passed to the DMARC module, along with the Author’s domain. The DMARC module then tries to retrieve the DMARC policy from the DNS for that domain. If it finds a policy, it uses this, along with the SPF and DKIM results, to decide whether the email passes or fails the DMARC check.
  5. Delivering the email: Based on the DMARC result, the Recipient’s mail service either delivers the email to the Recipient’s inbox or takes some other action, like sending the email to the spam folder.
  6. Providing feedback: If requested, the Recipient’s mail service collects data from the email delivery session and uses this to provide feedback to the Domain Owner. This feedback can help the Domain Owner understand how their emails are being received and whether there are any issues they need to address.

Remember, this is a simplified explanation. In reality, DMARC involves a lot of complex processes and technologies. But hopefully, this gives you a basic understanding of how it works.

Was this helpful?

0 / 0

Leave a Reply 0

Your email address will not be published. Required fields are marked *