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ARC-Authentication-Results
Learn what the ARC-Authentication-Results header records, how it preserves SPF, DKIM, and DMARC results, and how DMARCeye validates authentication chains.
Jack Zagorski
Oct 6, 2025
What is ARC-Authentication-Results?
The ARC-Authentication-Results header is part of the Authenticated Received Chain (ARC) framework, designed to preserve email authentication results as a message passes through intermediaries such as mailing lists, forwarders, or gateways. It records the results of SPF, DKIM, and DMARC checks at each hop, ensuring that downstream systems can verify the message’s authentication history.
ARC was developed to solve a long-standing problem in email authentication: when messages are legitimately forwarded, they often fail DMARC alignment because headers or sending IPs change. The ARC-Authentication-Results header ensures that a receiving server can see what the authentication results were when the message first arrived.
How ARC-Authentication-Results Works
When a message passes through an intermediary mail server that supports ARC, the server adds three headers:
ARC-Seal- Verifies the integrity of the ARC chainARC-Message-Signature- Signs the message contentARC-Authentication-Results- Records authentication results such as SPF, DKIM, and DMARC
Example ARC-Authentication-Results header:
ARC-Authentication-Results: i=1; mx.example.net; dkim=pass header.d=example.com; spf=pass smtp.mailfrom=example.com; dmarc=pass header.from=example.com;The “i=1” indicates the position in the chain (first hop), while each authentication result is clearly listed. When the next server receives the message, it can validate the chain and confirm that no data was altered in transit.
Benefits of ARC
- Preserves authentication results across forwarding and mailing lists
- Prevents false DMARC rejections
- Improves trust in intermediary relays and gateways
- Provides visibility into message handling across systems
ARC-Authentication-Results and DMARCeye
DMARCeye parses and validates ARC-Authentication-Results headers within analyzed messages to understand how authentication outcomes evolve across mail relays. By correlating these results with DMARC reports, it helps identify legitimate forwarding systems and confirm that trusted intermediaries maintain message integrity.
This visibility helps organizations avoid false positives, preserve deliverability, and maintain authentication continuity across complex mail routing environments.
- AI-powered monitoring, analysis, and recommendations
- Smart, configurable alerts
- Easy management dashboard gives full domain overview (great for agencies, schools and universities, and any other organization managing multiple domains)
Sign up for a free trial of DMARCeye today and secure your email domain.
To learn more about DMARC and DMARC-related terms, explore the DMARCeye Glossary.