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DKIM2: Email Signing Gets a Ground-Up Rebuild to Stop Replay and Survive Forwarding
A revived IETF working group is rebuilding DKIM from the ground up. DKIM2 (draft-ietf-dkim-dkim2-spec, authored by engineers from Yahoo, Google and Fastmail) signs every hop, binds each signature to the SMTP envelope to stop replay, records reversible "recipes" so forwarding no longer breaks DMARC, and routes provable bounces up the chain - and a companion draft retires ARC into it. It is real enough to watch (working code exists), but still a draft: do not deploy it in production yet.