Domain-based Message Authentication, Reporting and Conformance (DMARC) is an email validation system designed to detect and prevent email spoofing. It is intended to combat certain techniques often used in phishing and email spam, such as email messages with forged sender addresses that appear to originate from legitimate organizations. It provides a way to authenticate email messages for specific domains, send feedback to senders, and conform to a published policy.

DMARC is designed to fit into the existing email authentication process of IMSVA. The way it works, is to help email recipients to determine if the purported message aligns with what the recipient knows about the sender. If not, DMARC includes guidance on how to handle the non-aligned messages. DMARC requires that a message passes the Sender Policy Framework (SPF) or DomainKeys Identified Mail (DKIM) signature check.

By defining DMARC settings, IMSVA allows you to add domain names for DMARC verification, set IP addresses to bypass DMARC verification, and specify actions to take on messages that fail DMARC verification.