https://paulgraham.com/spam.html

I think all the parts were invented by other people, but he got the right mix to make it work.

It's also like the wheel. Before it was a huge problem and no one know how to solve it. Now it's invisible.

Note that all modern versions use enhanced variants with a lot or trick to make it better.

Every invention is made of other inventions all the way back to big rock and sharp stick.

So yes Bayesian spam filtering was impressive for its time. I remember it being done locally in mail clients.

It’s also one of the early popular deployments of a form of “AI” but that was still during the hangover from the first AI bubble when you had to call it “machine learning.”