One thing you can do is enable Spam Assassin. In your cPanel under Mail find Spam Assassin in the list of links. Click on the "Enable Spam Assassin" button to enable this feature. All spam will be clearly labeled as such form now on and will be easier to delete.

Optionally, you can choose to have all email marked as spam deleted immediately. The button to do this is right below the "Enable Spam Assassin" button. You can also configure the options for Spam Assassin to make it more or less strict.

Additionally, you can enable Spam Box and have all emails marked as spam by Spam Assassin sent there instead of to your inbox.