Email glossary · Practical guide
ARC: authentication evidence across intermediary handling
Authenticated Received Chain, or ARC, carries authentication-related evidence through intermediary handling. A receiver decides how to use that evidence; an ARC header is not an automatic bypass.
Reviewed · Examples are illustrative
Who this helps: Readers checking a term before making an outreach or mailbox decision.
Meaning and common confusion
Forwarding and mailing-list processing can complicate evaluation of the final message. ARC can help a receiver consider earlier observations, but the intermediary's trustworthiness and the chain result matter. It does not excuse an incorrectly configured original sender or guarantee inbox placement.
Worked example
This is a synthetic illustration, not a customer result or a live configuration to copy.
Original sender → intermediary → destination
Intermediary records authentication evidence and seals its contribution
Destination evaluates the chain and local trust
Do not equate 'ARC present' with 'recipient must accept'.Checks to make
- Identify the intermediary involved in the affected route.
- Inspect the complete receiving result rather than one header name.
- Compare direct and forwarded controlled messages.
Next step and limits
Use the ARC explainer when indirect mail flow is the actual issue. Adding arbitrary ARC-looking text to a message is not valid sealing. The provider or intermediary must implement the protocol correctly, and the recipient remains in control of handling.
Source references
Worked examples are illustrative. Editorial procedures are suggested methods, not measured performance claims or promises of additional product features.
Related guides
- ARC email authentication: evidence across an indirect mail path →
- Email forwarding and deliverability: test authentication and reply visibility separately →