keep marking it as spam. These places may keep going after you from different adresses for a while so you have to just keep marking it as spam until they stop. Don't worry it will after a while
Spam is from websites you've gone to and typed your email address into. All you have to do is unsubscribe (every email from spam has a link at the bottom). It will take a lot of time, but it works. I made a new email for myself and never use it in forms and stuff, and i dont have a single piece of spam, ever.