To update your email preferences, scroll to the bottom of any email you've receive from FEE and click the Email Preferences link. This will also allow you to opt back in to email if you've unsubscribed accidentally.
If you want to unsubscribe from all marketing emails you can do that here.
If you want to turn off browser push notifications (new article pop-ups) this must be done from your browser settings. PushCrew has published an excellent guide with a walk-through for all major browsers.