Posts tagged: arc
How to Read Email Headers: Decode the ARC Set
How to read email headers line by line: trace the Received chain, find your trust boundary, and decode the ARC set. Walk one real dump, then analyze yours.
DKIM2 Explained: The 2026 Successor to ARC and DKIM
DKIM2 is the IETF's per-hop chained-signature successor to ARC and DKIM. Seven active drafts, five contested questions, and what admins track in 2026.
ARC Email Authentication: Forwarded Mail in 2026
ARC email authentication carries SPF, DKIM, and DMARC verdicts across forwarding hops. Real headers, cv=fail debugging, trusted-sealer fixes, IETF status.
DMARC Fails on Forwarded Emails: Why ARC Is the Fix
Forwarded emails fail DMARC because SPF breaks in transit. See why, when DKIM survives, and how ARC seals the chain across every forwarding hop.