Go to your Settings app Touch Wi-Fi (for Wi-Fi only iPads) and make sure that Wi-Fi is ON Then, make sure that there is a check mark next to an available Wi-Fi network. If there is no checkmark, touch an available Wi-Fi network and “join” the network. Input a passcode if prompted. On 4G iPads, touch Settings and then Cellular Data Touch View Account and make sure that your login information is correct
If you are still having trouble getting an email or getting an error message, it is time to go to the actual email settings for the account in question.
Touch the Settings icon Touch the Mail, Contacts and Calendars tab Touch the specific email account that is giving you trouble. Touch the Account tab on the next screen. Verify that the Email and Password fields are correct. It is sometimes easiest to simply retype them and see if in the verification process this fixes the problem.