DMARC
Definition
Domain-based Message Authentication, Reporting and Conformance. A DNS policy that stacks on top of SPF and DKIM, telling receivers what to do (none, quarantine, reject) on failure, and where to send aggregate (rua) and forensic (ruf) reports.
Related terms
- DKIM
- DomainKeys Identified Mail. A cryptographic signature placed in a DKIM-Signature header. The signing key sits on the sending server; the public key...
- MTA
- Mail Transfer Agent. The server that relays mail server-to-server. Postfix, Exim, Sendmail and Microsoft Exchange are the common implementations. Speaks SMTP.
- MUA
- Mail User Agent. The client the user sees. Outlook, Thunderbird, Apple Mail, Gmail web, Spark, mobile apps. Speaks SMTP outbound and IMAP...
- Received Header
- A header line prepended by each mail server that accepts a message in transit, recording the server's own identity, the IP or...
- SPF
- Sender Policy Framework. A DNS TXT record on the sender domain that lists the IP addresses authorised to send mail for that...
Explained in
- Email Forensics: Protocols, Header Tracing, Spoofed MailDomain-based Message Authentication, Reporting and Conformance. A DNS policy that stacks on top of SPF and DKIM, telling receivers what to do (none, quarantine...