[novok]

Google gmail spam algo is heavily trained by users pressing the spam button. Do spammy things , get marked spam by joe average and do it enough and your emails are marked spam, no explicit action required. It also means that most political email is marked as spam.

[rconti]

I find it to be fairly awful actually. I've noticed over time it's just become what feels like a 5-position slider. I'm hesitant to mark Spam messages as Spam, because I'll immediately start getting a % of legit messages sent to spam. Un mark one of those, and suddenly I'm getting spam again.