How do you send email to trash without opening it. In the new email.

Sometimes I don't like to open emails that I have no idea where they come from(security), I like to just send them to trash(security). Once I get them to trash I know how to select all and then delete in trash. I can't however find a way to select several new emails and send to trash without opening. I am like just missing something. No one would ever devise a email where you had to open everyone of them  before sending to trash.