So I would expect, especially in a RankBrain world, Google will be making spam detection and search quality more machine learning based in the near future.

Gmail’s AI-powered spam detection is its biggest security upgrade in years Gmail's spam filters can now understand "adversarial text manipulations." ...

The big picture: Gmail's latest update introduces AI-powered spam detection to protect users from unsolicited junk mail. This upgrade not only enhances user security, but also significantly ...