Most spam filters do silently delete messages that they are particularly confident about. But spam detection is not black and white. The existence of "maybe" s

Most spam filters do silently delete messages that they are particularly confident about. But spam detection is not black and white. The existence of "maybe" spams means that you need to let some through. Having a separate folder is still useful because you can check it less often, and have no notifications for it. I check mine every couple of days or so. No email is so urgent that I need to see it in 24 hours.