Create a DMARC record in the correct format. A basic DMARC record looks like this: v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com; Publish the DMARC record in your DNS. This usually involves adding a TXT record to your domain's DNS settings. Monitor the DMARC reports to identify any issues and adjust your DMARC policy accordingly (e.g., from "none" to "quarantine" or "reject").