I hope against hope that AI spam detection never becomes a thing. At least with today's methods, I can tell a person why their message was marked as spam. If AI detection becomes the norm, all I can do is shrug and say, "Sorry, it's the algorithm."
Gmail is successful because it naturally is the biggest honeypot. Most antispam API filters are like accumulators. When a trend is detected, the rest are protected. But overall, it's about scale.
