> I found a simple solution
> Not a spam solution
> The only way to prevent spam
I personally don't believe spam currently can be solved with some single magic pill; every solution has limitations. If nothing is perfect, something better could emerge out of an intersection of the least damaging things.
> because spammers will not add the ephemeral key to their spam messages. You will only delete from compliant sender's
If we decide it's a useful and safe feature, we could make it a spec requirement. Not having the key from a non-contact (whoever we never responded to) could be one of the heuristics for spam (supplementable by locally running spam detection models, public trust rank, etc.): these messages could be put into a "potential spam" UI folder.