Common Temporary errors are following:
TAE 1, 2, 4, 6, 8, 14, 15, 21, or 46
Temporary Error 17
Most of these errors are caused by heavy traffic on the At&t network. In most cases, they are resolved in just a few minutes, though some may take few hours.
If you receive any errors, first refresh your Web browser, then try to access your Att email account again. If this doesn’t work, then try the following steps:
Log out of your Att email from all devices.
Clear your browser’s cache and cookies.
Restart your browser, and log in to your Att email account.
If these steps don’t resolve the error, Please contact Att email support on 1-877-827-1416.