We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Unable to authenticate to Outgoing server (SMTP) outbound.att.net

  • 2 replies
  • 2 have this problem
  • 4 views
  • Last reply by sfhowes

more options

I have not been able to use my Thunderbird email since April 2023. I called AT&T Several times, changed the password, changed the security questions and the Security key. Tried using the same password on Thunderbird and get these messages. This has happened twice before with No idea why it happens, All three times it took Weeks to get it working again. Your website offers no working option. Please provide a way to us to get HELP! I need my email, Please help me with this. Janell Coker

Login to server outbound.att.net with username jjcinhim@sbcglobal.net failed

Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) outbound.att.net. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'.

I have not been able to use my Thunderbird email since April 2023. I called AT&T Several times, changed the password, changed the security questions and the Security key. Tried using the same password on Thunderbird and get these messages. This has happened twice before with No idea why it happens, All three times it took Weeks to get it working again. Your website offers no working option. Please provide a way to us to get HELP! I need my email, Please help me with this. Janell Coker Login to server outbound.att.net with username jjcinhim@sbcglobal.net failed Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) outbound.att.net. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'.

All Replies (2)

more options

A secure mail key is required for ATT mail for both incoming and outgoing mail. https://www.att.com/support/article/email-support/KM1240308/

more options

Remove the entries from Saved Passwords in Settings/Privacy & Security, check the server settings with the AT&T site, generate a new secure mail key, restart TB, and enter the key when asked for a password.

https://www.att.com/support/article/dsl-high-speed/KM1010523/