On Tue, 4 Jan 2022 at 07:15, Phillip Hallam-Baker <phill@xxxxxxxxxxxxxxx> wrote:
On Mon, Jan 3, 2022 at 2:46 PM John Levine <johnl@xxxxxxxxx> wrote:It appears that Phillip Hallam-Baker <phill@xxxxxxxxxxxxxxx> said:
>The big benefit of moving to a separate infrastructure in which every
>message is authenticated and subject to access control with a default deny
>posture is we can leave the SMTP anti-spam heuristics behind.
Well, for about 15 minutes until we are reminded the hard way that
"authenticated" is not a synonym for "not spam". Spammers are if
anything better at DMARC, DKIM, et al., than legit senders.authenticated and subject to access control with a default deny postureThe access control is the key. J random grifter cannot send Alice spam BECAUSE SHE HAS NOT AUTHORIZED HIM TO SEND MESSAGES TO HER.
And how does one legitimately get such authorization? By messaging her on Twitter?
The reason that email remains ubiquitous is not because it's broken, it's because it remains the sole method by which one arbitrary endpoint can contact another. This is the same as the telephone, and successful walled gardens - such as WhatsApp - have emulated the same level of default access.
XMPP also does this, but many users block anyone without a presence subscription. The result is that there's an increasing amount of spam based around presence subscription requests. A solution based on the "contact request messages" you suggest will have exactly the same problems, and result in exactly the same behaviour.
If you have a communication path, people will abuse it. If you have no communication path, people will find one, or else your solution will fail.
In some ways, spam isn't a definition of failure, it's a measure of success.
Dave.
