For 10 years we have been referring ATT customers to the page on the ATT web site that says they need a mailkey to access their mail not their password. Personally I am sick of providing free support for ATT so they can make huge profits through their omission of good user support.

https://www.att.com/support/article/email-support/KM1240308/

Thanks for the link, Matt. I personally would leave ATT if I could, but I need the emails in the file folders I've created on Thunderbird. About 10 years ago microsoft dumped my email account and I lost all my contacts and folders with important information. Sometime after that ATT helped me set up a key, but it turned out to be good for one use. I haven't been able to receive email on my ipad purchased a year ago and can't restart it on my older one. Hopefully one key will open mail on both my ipads and not mess up the yahoo account on my desktop or my iphone which are currently working. Calling ATT for help takes over an hour each time and often requires multiple calls. Your help is appreciated. I am not tech savvy. Just trying to use the technology.