-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 In message <[email protected]>, Bron Gondwana <[email protected]> writes
>As I'm trying to implement DKIM2 DSNs, I am struck by very many things. > >1) they're only ever i=1; because the next hop has to remove the details and >create a new DSN. That's not correct ... a backup MX which implements DKIM2 could well add am i=2 DKIM2-Signature when forwarding the mail to the system that actually handles the domain's email. Now backup MXs are last century technology but I do not believe we should be outlawing them here. >2) they're only ever mf=<> > >3) they aren't modifyable (only ever a single message-instance, with no recipe) >3a) and the signed Mesasge-Instance of the headers they include already hashes >its own headers and can be verified. I don't think they should be modified, but if they were then the system that actually handled them (see comment on #1 above) can undo changes >4) their rt= must match the mf= of the top hop in the message; so can be >unambigously derived. > >5) their d= must match an rt= from the top hop of the message. *this is >required still* > >So we could really just create a very simple singleton header: > >DKIM2-DSN: d=example.com; [email protected]; h=<mival> s=sel:alg:digest I don't like this because of the complexity of having yet-another- header-field, leaving alone the remarks above. >This makes it really clear that this is a DSN. if that is important (and implementers may find that it is) then I would argue that a better way to signal this would be to prescribe what the Subject header field MUST be. > It is only ever expected to be >received by Bounce addresses, which will generally be dedicated processor >addresses which never see anything else, some mail is sent by individuals rather than ESPs (hard to remember some days) ... so I think you might mean that it would be unusual for DSNs to be forwarded back along a chain and the delivery to that forwarder (backwarder!) was not to a specialised address. - -- 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/AwUBakfvr2HfC/FfW545EQKq0wCg8vVOBWsLTeOLqzHDogvQxhDBsB4An2Gj mQkb9YeLRfZ+MnrQWd25Ylnc =pcs2 -----END PGP SIGNATURE----- _______________________________________________ Ietf-dkim mailing list -- [email protected] To unsubscribe send an email to [email protected]
