Your email address was showing in your screenshot so I asked the hosts to remove the image.
Have you tried force closing the mail app and then force restart the iPad? In order to force close the mail app, double tap the home button to get to the app switcher. Then swipe to find the mail app preview window. Swipe the window up and off the screen to closes the app.
In order to force restart the iPad, hold down on the home button and the sleep button until you see the apple logo on the screen. Then let go of the buttons and let the iPad boot up. If you see the slide to power off button, just ignore it until you see the Apple logo.