Deleting the mountains of email in your Inbox one at a time is an onerous task that requires time and a lot of patience. However, deleting all of your emails at once is not as hard as you might think. Even though there are a lot of websites that offer email addresses such as AOL, Google, Yahoo and Hotmail, these email systems are very similar. Using these systems properly, you can quickly and easily delete all your email at once.
Open your web-based email and log in using your username and password.
Click "New Mail" or "Inbox" to view your mail.
Click the very first check box that is on the line above the first email. This check box selects each email in your Inbox. If you need to keep certain emails, unselect the individual check boxes next to each email to prevent erasing them.
Press the "Delete" button in the webmail interface to delete all of your selected emails.
If you have accidentally deleted an email from your Inbox, simply click "Undo" or click the "Delete" or "Recently Deleted" folder to search for and restore the email.