How to delete an email without opening it?

I have always received some emails on my iPad. If the email is more than enough to load any images in the email confirming my email address for the spammer that sent the email, how can I delete it without making the mail visible? In landscape mode, there is the list of emails on the left, and the body of one email on the right.When you swipe on a mail further down the list from left to right, you