Then smaller email providers will have to be very picky about who they onboard. And/or the senders of such emails will have to be careful that every email is le

Then smaller email providers will have to be very picky about who they onboard. And/or the senders of such emails will have to be careful that every email is legitimately and actively desired by the recipients. Or there is no viable business here and we go without the extra emails, a not too bad tradeoff.