What is DMARC?
Domain-based Message Authentication, Reporting and Conformance — tying SPF and DKIM together.
DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email authentication policy that builds on SPF and DKIM. It tells receiving servers what to do when emails fail authentication checks — monitor (none), quarantine (send to spam), or reject (block delivery). DMARC also provides reporting so you can see who is sending email using your domain. For cold email, a properly configured DMARC record is essential for deliverability and protecting your domain from spoofing.