To delete an entire page of e-mail at a time.
Log on as you normally do and go to your inbox. You will see a list of your files in your inbox like the inbox shown below.
Click on the first e-mail so that the first e-mail is selected (see above).
Next hold down the SHIFT key.
While the shift key is depressed, click the bottom e-mail on the page. The entire column of e-mails should become highlighted (see below.)
If
you click on the 
delete key the whole column will be deleted.
If you have many pages you will need to delete each page individually.
Remember to go through and delete your e-mail frequently so it does not get too full.
Good luck!