What is Authenticated Received Chain (ARC)?
ARC, which stands for “Authenticated Received Chain,” is an email authentication standard designed to improve and secure the forwarding of emails. Email forwarding can sometimes break traditional authentication mechanisms, like DKIM (DomainKeys Identified Mail) and SPF (Sender Policy Framework), causing authentication failures for forwarded messages.
How does ARC authenticate forwarded emails?
ARC helps address authentication of email forwarding services to sign the email on behalf of the original sender, indicating that the message has been legitimately forwarded. This signature travels with the message, creating a chain of trust. Email receivers can then verify the authenticity of the email and determine that it has been properly forwarded.
The ARC protocol is particularly useful in scenarios where emails go through intermediaries, such as mailing lists or forwarding services. It helps maintain email authentication integrity across these intermediaries, reducing the chances of legitimate emails being marked as spam or phishing.