Authenticated Received Chain (ARC) is an email authentication standard designed to preserve authentication results as a message passes through multiple servers or intermediaries, such as mailing lists, forwarders, or helpdesk systems.
Normally, when an email is forwarded, SPF and DKIM checks can fail because the message is resent from a different server. ARC solves this problem by creating a verifiable “chain of custody” that records each server’s handling of the message.
This helps receiving mail systems decide whether to trust a message even if its SPF or DKIM results no longer align perfectly after forwarding.
When a mail server that supports ARC receives a message, it adds a set of headers (ARC-Seal, ARC-Message-Signature, and ARC-Authentication-Results) which capture the authentication state at that point in transit.
Each subsequent server that relays the message adds its own ARC headers, effectively building a “chain” of authentication results that can be verified by the final recipient’s mail system.
This allows legitimate messages that have been properly handled by trusted intermediaries to still be delivered, even when traditional SPF or DKIM validation fails along the way.
Without ARC, legitimate forwarded messages, like from mailing lists or automatic forwarding services, can appear suspicious to receiving mail systems and end up in spam folders or get rejected entirely.
ARC provides additional context for authentication, helping mailbox providers distinguish between malicious spoofing and legitimate forwarding.
In other words, it reduces false positives for properly authenticated mail that naturally passes through intermediaries.
DMARCeye helps organizations monitor how ARC interacts with SPF, DKIM, and DMARC results in real-world traffic. By visualizing authentication chains, DMARCeye makes it easier to spot where alignment breaks down and where messages are being altered or relayed.
This insight helps maintain both security and deliverability, especially for businesses that rely on mail forwarding or third-party services.
Sign up for a free trial of DMARCeye today and start protecting your email domain.
To learn more about DMARC and DMARC-related terms, explore the DMARCeye Glossary.