Understanding DMARC Forensic Reports (RUF)
Domain-based Message Authentication, Reporting, and Conformance (DMARC) is an email authentication protocol. It builds upon Sender Policy Framework (SPF) (RFC 7208) and DomainKeys Identified Mail (DKIM) (RFC 6376). DMARC allows domain owners to publish a policy in their DNS. This policy instructs receiving mail servers on how to handle emails that fail SPF or DKIM authentication for their domain.
DMARC also provides reporting mechanisms. Aggregate Reports (RUA) offer a high-level overview of email authentication results. They summarize pass/fail rates for SPF and DKIM, DMARC alignment, and sending sources. RUA reports are invaluable for monitoring email ecosystem health. However, they lack granular detail for specific delivery issues.
This is where DMARC Forensic Reports (RUF) become critical. RUF reports, also known as failure reports, provide detailed insights into individual email failures. When an email fails DMARC authentication and the domain's policy dictates, receiving servers can generate these reports. They contain redacted portions of the original message that failed authentication. This includes headers, subject lines, and sometimes URI snippets from the message body.
