DMARC builds on SPF and DKIM by allowing domain owners to specify how to handle emails that fail authentication checks. To implement DMARC, you need to create a DMARC policy and publish it in your DNS records. Here’s an example of a simple DMARC record:
In this example, "v=DMARC1" specifies the version, "p=none" indicates that no specific action is required for failed checks, and "rua=mailto:dmarc-reports@example.com" is the email address where aggregate reports are sent.