Hi there and welcome
To get them on the iPad, on the iPad go to Settings, Mail
Then Tap Yahoo (as AT&T uses this)
Enter in your account details and it should then be added
If you have continued problems, or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.