I tried to operate my own email server as well on a VPS, and I have been thinking that the way to solve these problems is to solve the problem of spam itself. Detecting spam puts the costs on the email providers... when the costs should be born by spammers. Perhaps some sort of digital stamp (digital signatures similar to stamps on physical envelopes) for each email sent paid for with micropayments in a cryptocurrenc…
> Small cost per email like 0.01 cents that is trivial for legitimate senders but not for bulk-sending spammers Given how much is spent on ads, I’d say that an email is still worth more than that. So, what you get is spammers paying minuscole amount of money to skip the spam filter and killing the idea at the root. Or they can simply steal these credentials from one of the millions of hacked sites and cause additiona…
[1] It's not quite. See sibling post to yours.