A charity API. When people outside my contacts list first email me, I would (auto) generate and send a charity donation link to them, and once the donation is verified, I'd let their mail through.
I've been thinking about a captcha-like "prove you're not a bot/spammer" system for emails and I think charity donations would be a good test of that.
That sounds horrifying though. Instead of captcha, a user now has to navigate a random website and a payment processor to obtain access.
So much potential to be on the hook for shady transactions just to let an email through.
Admittedly, reality might be different (I won't know until I actually have this feature), but in my mind this is a good thing ¯\_(ツ)_/¯ I would still receive emails from my contacts and I can add new people to contact list if I meet them through other channels first. This would only apply to strangers.
I didn't quite get your last sentence though. Who would be on the hook and why? A 1 dollar donation to a reputable charity wouldn't be a shady transaction.
I've been thinking about a captcha-like "prove you're not a bot/spammer" system for emails and I think charity donations would be a good test of that.