Technical specifications repository
On this page, you find references to the authoritative technical specifications followed by dmarced to ensure secure email delivery via DKIM, SPF, and DMARC.
DMARC
The current DMARC standard, published in May 2026, is made up of 3 RFC publications: The first one laying out the foundation of how DMARC operates, the second covering DMARC aggregate reports, and the third one covering failure reporting.
- RFC 9989: Domain-Based Message Authentication, Reporting, and Conformance (DMARC)
- RFC 9990: Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Aggregate Reporting
- RFC 9991: Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Failure Reporting
The three RFCs above replace the following specification of DMARC. It is still relevant as many participants may not have updated their software to support the changes.