The solution is to add a small fee to each message proportional to the cost of reading it. This was the original idea behind hashcash before bitcoin used it for PoW. But you could also do it with a micropayments system such that the recipient splits some reward.

What a disgusting, clickbait title, surely we can do better? gaurav sood, owner of gojiberries.io is furious about spam, but has no answer

[dead]