I observe that most newbies using Gmail, Yahoo-mail, and others have thousands of email messages unread and unwanted messages. This often get me bewildered why liter your email box with messages from social networks media, Sport and News feeds. Basically your email inbox should be void of unwanted emails. This is because you, may not know which is spam message and the real email.
Now click the Delete Icon Tool As seen Bellow
When the First Page gets deleted, click the select all Box and Click Delete till you Delete them all.