Just got an Email account at ATT.net but am recieving error message

How are you trying to access the email?  Who/what is reporting that error?  If that is from an email client app try logging into the webmail to see if you account (email address) and account password are working.  Go to start.att.net  and click the mail icon in the upper right.

Thanks

the message is coming when I try to access the email account I joined from the web you indicated...

 start.att.net  and click the mail icon in the upper right.

 This is the full message that I am getting on the web to start the email access to my account.

SAML 2.0 authentication failed

Error details

Stack trace

Still the same problem is persisting.

Try a different browser for comparison.  Are you sure your att account is even active?  Call tech support for verification (800-288-2020).

I tried other browsers too the same response is coming and the account is active because it is confirmed and my sign in to the other news,,, entertainment all the other features is coming but not the email when I press the mail to open it is responding the same in all.

thanks

Well then instead of the 2020 number call the Digital Assistance Center (877-273-2728).

Have you had any luck getting around this yet?  I too just got new service and am unable to log into the mail server.  When I click on the Mail icon in the upper right, or the Mail word in the left hand menu, it takes me to a new page and I get the same error message.  I've tried this on several different browsers and it happens in each of them.  

The link it takes me to is: https://mail.yahoo.com/?.partner=sbc  but then that updates to: https://loginprodx.att.net/FIM/sps/ATTidp/saml20/logininitial?RequestBinding=HTTPPost&PartnerId=https%3A%2F%2Flogin.yahoo.com%2Fsaml%2F2.0%2Fatt&.lang=en-US&Target=https%3A%2F%2Fmail.yahoo.com%2F%3F.partner%3Dsbc

After which the error is displayed (see attachment)

Having same problem here.  The exact same error, same screen as captured above.  So frustrated. Have had this account for about 10 years.