Volume spikes around promotions trip ISP rate limits unless warmed and segmented.
What ARC (Authenticated Received Chain) is#
ARC preserves authentication results across intermediaries such as mailing lists and forwarders. Each hop signs the results it saw, so the final receiver can trust an earlier pass even if SPF or DKIM broke in transit.
Why it matters#
Forwarding and mailing lists are the largest source of legitimate DMARC failures. ARC lets receivers accept mail that would otherwise be quarantined under p=reject.
Implementation plan for ecommerce stores#
- Check whether your inbound gateway or mailing-list software supports ARC sealing.
- Enable ARC sealing on any system that modifies and re-sends mail.
- Verify ARC-Seal, ARC-Message-Signature, and ARC-Authentication-Results headers appear on forwarded mail.
- Confirm downstream receivers (Gmail, Microsoft) honor your seals by checking Authentication-Results for arc=pass.
Priorities specific to ecommerce stores#
Volume spikes around promotions trip ISP rate limits unless warmed and segmented. Weight your effort toward the steps above that address this constraint first, and measure with metrics that match how ecommerce stores generate value from email.
Common mistakes#
- Expecting ARC to fix your own outbound authentication; it only helps intermediaries.
- Trusting ARC from unknown sealers, which reopens the spoofing door.
Frequently asked questions#
Do I need ARC as a sender?
No. ARC is implemented by intermediaries and receivers. Senders benefit indirectly when their mail is forwarded.
Which providers honor ARC?
Gmail, Microsoft, and Yahoo all evaluate ARC when deciding whether to override a DMARC failure.