Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
Lets try going to settings, mail, and remove the earthlink account.. Heres how
Then, lets hold down the sleep / wake and home button for 30 seconds. The ipad should turn off. Then, turn it back on.
And now, add the earthlink account again following these steps.
Let me know if this works, and if not let me know where you get stuck at .
I strive to provide great service, and greatly appreciate a 5 star rating clicked and submitted when you are satisfied.. I always answer follow up questions.Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.