-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 In message <[email protected] il.com>, Wei Chuang <[email protected]> writes
>On Thu, Sep 17, 2026 at 4:42AM Richard Clayton <[email protected]> >wrote: >> In message <[email protected] >> il.com>, Wei Chuang <[email protected]> writes >> >> > Also we can require the From header to be aligned at every SMTP >> > transaction boundary which implies From header munging at those >> > boundaries. >> >> to a first approximation no forwarding system does this today >> >> this is not going to fly >> > >Not sure which part you disagree with. I do not believe that forwarding systems change the RFC5322 From header field when they forward email. Mailing lists do ... but that is because they have altered the content. Alumni forwarders that mangle the email may do so as well ... but the type of forwarder that just takes everything arriving for an email address and sends it on to somewhere else does not touch the RFC5322 - From header field > But AFAIK having DMARC evaluation >done at i=n will require relay forwarders to always mangle the From header >field before being sent to a DMARC mail receiver that will perform the >evaluation. Why would DMARC evaluation be done at i=n ... no-one has proposed that. There is an argument for doing DMARC evaluation at the highest i= where the RFC5322 From header field is changed. That is what systems do today because they are unable to recover the RFC5322 From header field as it was set at i=1 In DKIM2 a received can use recipes to recover the original i=1 RFC5322 - From header field and so it can feed that to its "enhanced-for-DKIM2 DMARC" evaluator. It can also persuade an MUA that handles the email thereafter to display that value. >It's possible I'm overreading the relationship >between draft-ietf-dkim-dkim2-spec and this proposal, and if fact what you >are proposing is to support i=1. If so, as Pietro points out, evaluating >DMARC at i=1 can simplify this proposal. I am in favour of the "enhanced-for-DKIM2 DMARC" and relevant MUAs using the i=1 value of the RFC5322 header field. But whatever we decide, the notion that every hop rewrites the RFC5322 - From header field is nonsense. Your draft says that. If you think my - -spec document says that then please cite the paragraph and will ensure that the text is modified appropriately - -- richard @ highwayman . com "Nothing seems the same Still you never see the change from day to day And no-one notices the customs slip away" -----BEGIN PGP SIGNATURE----- Version: PGPsdk version 1.7.1 iQA/AwUBaq/6cGHfC/FfW545EQJSlQCfVzscp5GK+GdDZWMp8z46bs+SKa0AoOM7 /rUlHyds65G5CamVUWbBAhuG =fWf3 -----END PGP SIGNATURE----- _______________________________________________ Ietf-dkim mailing list -- [email protected] To unsubscribe send an email to [email protected]
