How to stop spam emails from reaching your inbox

Spam—phishing, marketing, and scam emails—is annoying, that we can all agree on. One Macworld reader wants to take the ultimate step is stopping these emails.
Is it possible to set one’s iMac, MacBook Pro, iPhone and iPad to ensure scam, phishing, and marketing emails are blocked? I’d be grateful for any information you can provide.Would it were so! Would it were so. Unfortunately, the basis of internet email is that every part of the system more or less mostly trusts eve