DMARC is Domain-based Message Authentication, Reporting and Conformance, a technical standard that helps protect email senders and recipients from advanced threats that can be the source of an email data breach.

DMARC builds upon the DKIM and SPF authentication protocols to detect when a threat actor is using a domain without authorization. DMARC is used to block the delivery of unauthenticated email.

DMARC email security provides a way for domain owners to outline their authentication practices and specify the actions to be taken when an email fails authentication. DMARC also provides a way for recipients to report on email that fails authentication.

DMARC benefits businesses by providing another layer of protection that guards against attacks like impersonation fraud, where an attacker uses a legitimate domain to send a fraudulent message.

DMARC checks whether emails have been sent from an authorized IP or domain, specifying how domains can be contacted if there are authentication issues and provides the forensic information needed to monitor and quarantine suspect emails. 

DMARC proactively reviews email message headers to ensure the accuracy of the information provided. DMARC works with DKIM and SPF authentication to verify legitimate emails before delivery and reject malicious emails before they are delivered.