It's unclear from your post, which adverts appearing where that you're referring to.
If you mean the ads that appear above your Inbox when you log in via Sky.com - use an email app instead
If you mean advertising emails that appear in your Inbox or Junk folders, move them to your Trash folder and empty it.
If you mean preventing advertising emails from arriving, it's not achievable. The best you can do is to keep, marking them as spam and eventually the email system, will learn to divert from to your Junk folder rather than send them to your Inbox.
