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email authentication debugging

Headers & MIME

The Authentication-Results Header: Parsing SPF, DKIM, DMARC and ARC Verdicts (RFC 8601)

Alaa 27 August 2026

The Authentication-Results header (RFC 8601) records SPF, DKIM, DMARC, and ARC verdicts per message at the receiver. Covers the exact format with authserv-id and ptype fields (smtp.mailfrom, ...