You might have plenty of unnecessary emails on Yahoo! Mail that you want to get rid of. You can delete all your emails in Gmail easily, but for Yahoo it is a little bit more complicated.
There is a Select All option in Yahoo, but it can only delete a certain number emails you have loaded.So if you want to delete all your emails you will need more time than other email providers.
To get started make sure you have a good internet connection and used updated major internet browser like Google Chrome, Internet Explorer, Mozilla Firefox.