On Mon, Oct 14, 2024 at 01:03:48PM +0900, Nico Schottelius via Postfix-users wrote:
> We at ungleich [0] plan to switch towards IPv6 only mail services A substantial fraction of email domains are IPv4-only? Why is IPv6-only a good idea at this time? > in the near future and we would like to "revolutionise" the way how we > handle mail while we do this step. This mail is to discuss the idea > and get some feedback from the community of other postfix users. Sounds like marketing getting ahead of sound engineering. These are not new ideas, they just don't work... > - All participating mail servers are IPv6 only [1] > - Every participating entity has an OpenGPG keypair [2] Unlikely to scale. > - Every mail server of an entity only accepts email, if the sending > mail server's public key is signed by a trusted key Any system that is open and scales will have bad actors. If the system never becomes popular, it is irrelevant. If it becomes popular, the bad actors will be early adopters. > - Additionally there might be a negative / exception in this stating: > A) if the key is X, refuse mail > - Note that this cannot apply to signatures, because anyone can sign a > key and if we were to refuse a key based on its signatures, a > blacklisted key could render valid keys invalid You're proposing something similar to <https://www.ietf.org/rfc/rfc3514.txt>. > The underlying assumption is as follows: > > - This network of trusted entities starts very small > (in our case we sign a couple of friendly other ISPs in Switzerland, were > we are located at) If this is a small club, there are surely simpler designs. You could model yourself on EMIG (Email Made in Germany). > - Those ISPs do the same, so the network grows > - Eventually multiple networks join, when the first participant of > network A starts to sign a key of network B > - A decentralise approach as this one will help to build a more stable > Internet The web of trust does not scale. > - I'd like to hear what you think about the approach > - I was wondering what would be the best approach to incorporate this logic > into postfix To authenticate receiving systems, consider DANE. To authenticate sending systems, don't bother, there's no way to build an open network that somehow has only the good guys participating. -- Viktor. _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
