What is DMARC?

A policy telling receivers what to do with mail that fails SPF and DKIM alignment.

A DMARC record at _dmarc.domain sets p=none, quarantine or reject and where to send reports. Gmail and Yahoo require DMARC for bulk senders since 2024; p=none only monitors and doesn't protect against spoofing.

Related terms

• DKIM: DomainKeys Identified Mail: cryptographic signatures on outgoing email.
• MTA-STS: A policy that forces encrypted (TLS) delivery of email to a domain.
• BIMI: Brand Indicators for Message Identification: shows a brand logo next to authenticated email.