I'm not sure you realize your proposal's only contribution is to worsen spam. You are unwittingly creating an incentive for email providers to lift anti-abuse filters and to maximize the volume of spam delivered to you.
Some sort of payment scheme is really the best, most durable option. The problem of mailing-lists and personal correspondence could be solved by an exclusion mechanism where the recipient effectively whitelists senders, explicitly or implicitly (e.g. whitelist a replying-sender automatically if a recipient initiates a conversation).
So the end result will be more spam and fewer legit E-mails.
Hormozi could charge $1,000 to get into his read box.
We could refund people, add them to a whitelist - and return a 405? payment required by default and things change in interesting ways when the amount is variable.