How machine learning removes spam from your inbox

This article is part of "Deconstructing artificial intelligence," a series of posts that explore the details of how AI applications work. Of more than 300 billion emails sent every day, at least half are spam. Email providers have the huge task of filtering out the spam and making sure their users receive the messages that matter. The line between spam and non-spam messages is fuzzy, and the criteria change over time. From various efforts to automate spam detection, machine learning has so far proven to be the most effective and the favored approach by email providers.