[nmh-workers] ARC: Forwarding with DMARC, DKIM, and SPF.

[Ralph Corderoy]

Hi,

Whilst investigating a friend's question about ~/.forward in the age of
DMARC, etc., I came across Authenticated Received Chain for email that
seems to be heading to an RFC.

    ARC is intended to be used by Internet Mail Handlers who forward or
    resend messages, with or without alterations, such that they will no
    longer pass the SPF [RFC7208], DKIM [RFC6376], and/or DMARC [RFC7489]
    mechanisms when evaluated by subsequent message handlers or the final
    recipient.  In such cases ARC may provide useful information about
    the message before the forwarding and/or alterations took place, and
    recipients may choose to use this information to influence delivery
    decisions.
        ― https://tools.ietf.org/html/draft-ietf-dmarc-arc-usage-06#section-1

    http://arc-spec.org/
    http://arc-spec.org/?page_id=79

I haven't studied it in any detail yet, and don't know when I will find
the time, but I thought it existence might be of interest to some on the
list, and wondered if dist(1) and others would be users of this new
technique.

Cheers, Ralph.