8 ms·

It would be nice if these big mail services accepted actual proof of work as a way to guarantee that your mail gets through. Maybe someone could extend SMTP wit

It would be nice if these big mail services accepted actual proof of work as a way to guarantee that your mail gets through. Maybe someone could extend SMTP with a bitcoin-like challenge where the server sends the client a nonce and a difficulty factor, and the client has to reply with a suffix that you can append to the nonce so that the whole string hashes to something with the corresponding number of zeroes at the end. People sending personal emails will be happy to burn a penny of CPU time as "postage" but spammers won't be able to send their spam profitably, especially if you increase the difficulty factor based on how many emails you've sent in the last hour.

esotericn 7y ago
https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash > Hashcash was proposed in 1997 by Adam Back[1] and described more formally in Back's paper "Hashcash - A Denial of Service Counter-Measure".[2]
- brianpgordon 7y ago
  I guess the idea was too obvious to be original. I'm surprised that it inspired Bitcoin instead of the other way around though.
deleted 7y ago
[deleted]
jcranmer 7y ago
> People sending personal emails will be happy to burn a penny of CPU time as "postage" but spammers won't be able to send their spam profitably The problem with this idea is that spammers don't use their own computer, they borrow other people's computers to send the spam. It also heavily penalizes people who legitimately need to send bulk email.
- Nullabillity 7y ago
  > It also heavily penalizes people who legitimately need to send bulk email. Aka spammers.
  - dasil003 7y ago
    Believe it or not there are email newsletters and mailing lists that people legitimately want to receive.
    - jcranmer 7y ago
      Such as the Linux kernel mailing list.
      - amelius 7y ago
        Yeah, but for bulk-mail one could introduce "whitelists".
  - zbentley 7y ago
    (Note: deleted and moved here because I put it in reply to the wrong comment) I work for an email marketing provider (opinions my own, obviously), and I was extremely surprised how many people genuinely want to receive lots of commercial bulk marketing email. And by "want to" I don't mean "don't mark as spam", I mean "continually sign up for different marketing newsletters, and consistently use links in newsletters/marketing emails to make purchases from multiple companies". It's an alien phenomenon to me, and it may be a minority of bulk email, but it definitely is useful to a lot of people. Maybe it's their equivalent of coupon-clipping-based shopping, or maybe they just like learning about things to buy in that format? I have no idea. That aside, the last thing an email marketing platform wants to do is send spam. Every time someone marks an email such a provider sends as spam, the reputation of their sending addresses is damaged, and therefore their ability to deliver mail to aforementioned people who want to receive them (and therefore the ability of the marketing platform to make money by facilitating that kind of desired email) is jeopardized. TL;dr there's bulk marketing email and then there's spam, and surprisingly little overlap (and overlapping incentives) between the people who send each.
- deleted 7y ago
  [deleted]
fanf2 7y ago
Proof of work proves not to work (2004) http://www.cl.cam.ac.uk/~rnc1/proofwork.pdf http://www.cl.cam.ac.uk/~rnc1/proofwork.pdf
- brianpgordon 7y ago
  The paper's argument assumes that the PoW scheme is required though. It could be an option which just guarantees that individual mail can get through, while still keeping the usual reputation-based spam filtering for clients which don't want to participate.
  - jcranmer 7y ago
    If there's one lesson from the history of spamming, it's that spammers are among the fastest adopters of anti-spam technologies. If PoW meant that spammers could only send 1/100th the email, but the email was 1000× more likely to actually show up in an inbox, spammers would jump on it in a heartbeat.
    - brianpgordon 7y ago
      That doesn't make sense. Each email is only worth so much to a spammer. They can't lose money on every email and make up for it with volume.
      - jcranmer 7y ago
        The value to spammers isn't in email delivered, it's the actual user engagement at the end of the process. A million messages delivered to the inbox is worth far more than a billion messages delivered to the spam folder.
        scarejunba 7y ago
        Yeah, but if the marginal cost of the next message is higher than the marginal expected increase in revenue then they won’t. It doesn’t matter optimizing inbox delivery rates if per-delivery you lose money.
prirun 7y ago
It's an interesting idea, but wouldn't this be easy to abuse though, like Gmail could force Fastmail to do huge proofs of work before accepting their mail?

esotericn 7y ago

https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash > Hashcash was proposed in 1997 by Adam Back[1] and described more formally in Back's paper "Hashcash - A Denial of Service Counter-Measure".[2]

brianpgordon 7y ago
I guess the idea was too obvious to be original. I'm surprised that it inspired Bitcoin instead of the other way around though.

deleted 7y ago

[deleted]

jcranmer 7y ago

> People sending personal emails will be happy to burn a penny of CPU time as "postage" but spammers won't be able to send their spam profitably The problem with this idea is that spammers don't use their own computer, they borrow other people's computers to send the spam. It also heavily penalizes people who legitimately need to send bulk email.

Nullabillity 7y ago
> It also heavily penalizes people who legitimately need to send bulk email. Aka spammers.
- dasil003 7y ago
  Believe it or not there are email newsletters and mailing lists that people legitimately want to receive.
  - jcranmer 7y ago
    Such as the Linux kernel mailing list.
    - amelius 7y ago
      Yeah, but for bulk-mail one could introduce "whitelists".
- zbentley 7y ago
  (Note: deleted and moved here because I put it in reply to the wrong comment) I work for an email marketing provider (opinions my own, obviously), and I was extremely surprised how many people genuinely want to receive lots of commercial bulk marketing email. And by "want to" I don't mean "don't mark as spam", I mean "continually sign up for different marketing newsletters, and consistently use links in newsletters/marketing emails to make purchases from multiple companies". It's an alien phenomenon to me, and it may be a minority of bulk email, but it definitely is useful to a lot of people. Maybe it's their equivalent of coupon-clipping-based shopping, or maybe they just like learning about things to buy in that format? I have no idea. That aside, the last thing an email marketing platform wants to do is send spam. Every time someone marks an email such a provider sends as spam, the reputation of their sending addresses is damaged, and therefore their ability to deliver mail to aforementioned people who want to receive them (and therefore the ability of the marketing platform to make money by facilitating that kind of desired email) is jeopardized. TL;dr there's bulk marketing email and then there's spam, and surprisingly little overlap (and overlapping incentives) between the people who send each.
deleted 7y ago
[deleted]

fanf2 7y ago

Proof of work proves not to work (2004) http://www.cl.cam.ac.uk/~rnc1/proofwork.pdf http://www.cl.cam.ac.uk/~rnc1/proofwork.pdf

brianpgordon 7y ago
The paper's argument assumes that the PoW scheme is required though. It could be an option which just guarantees that individual mail can get through, while still keeping the usual reputation-based spam filtering for clients which don't want to participate.
- jcranmer 7y ago
  If there's one lesson from the history of spamming, it's that spammers are among the fastest adopters of anti-spam technologies. If PoW meant that spammers could only send 1/100th the email, but the email was 1000× more likely to actually show up in an inbox, spammers would jump on it in a heartbeat.
  - brianpgordon 7y ago
    That doesn't make sense. Each email is only worth so much to a spammer. They can't lose money on every email and make up for it with volume.
    - jcranmer 7y ago
      The value to spammers isn't in email delivered, it's the actual user engagement at the end of the process. A million messages delivered to the inbox is worth far more than a billion messages delivered to the spam folder.
      - scarejunba 7y ago
        Yeah, but if the marginal cost of the next message is higher than the marginal expected increase in revenue then they won’t. It doesn’t matter optimizing inbox delivery rates if per-delivery you lose money.

prirun 7y ago

It's an interesting idea, but wouldn't this be easy to abuse though, like Gmail could force Fastmail to do huge proofs of work before accepting their mail?