Thunderbird-AT&T email password glitch: a fix for one problem

BACKGROUND:

A few days ago (04/05/21), my AT&T email account, which I access through Thunderbird 78.9.0 (64-bit), stopped downloading emails. Thunderbird showed a message box with the message

"Sending of password for user ******@att.net did not succeed. Mail server inbound.att.net responded: Server error - Please try again later."

After many tries with no change in 24 hours, I recalled a vaguely similar situation last November on our iMac with my wife's AT&T email account. After several long chat sessions with AT&T, I learned that I had to establish what they call a "secure mail key". Apparently, this is a password specifically for their email servers. AT&T apparently decided to upgrade security between customer email clients and AT&T servers by requiring email servers and web site log on to use different passwords. Apparently, once a customer running Thunderbird is targeted, Thunderbird may no longer be able to send or receive email. I keep saying "apparently" because I did not receive an advance notice from AT&T on this. So I retrieved my notes on what I did for our iMac, which uses Apple Email. The procedure to fix this problem, which I had to modify for Thunderbird, is summarized below.

PROCEDURE:

• Solution is to first go to the AT&T web site and generate a "secure mail key".
• Then enter the password manager in Thunderbird and delete the current stored passwords for AT&T.
• Restart Thunderbird and request download of AT&T email.
• At Thunderbird's request, enter the secure mail key as the new password. Do once each for incoming and outgoing servers.

DETAILS:

Go to the AT&T web site:

• https://currently.att.yahoo.com/
• Log on for the email address under consideration (if you have more than one).
• Click tab myATT.
• Click Profile icon (roughly the shape of little person).
• Scroll down to My linked accounts.
• Scroll down to Manage secure mail key and click.
• Click Add Secure Key.
• Enter a nickname for the key.
• When the secure key is displayed, copy and paste it to somewhere retrievable (e.g., text file).
• Log off of web site.

Open Thunderbird and remove existing passwords for the email address under consideration:

• Go to Preferences/Security and Privacy/Passwords/Saved Passwords.
• Will show a table of saved URLs and email addresses.
• Note that there is a button to unhide the passwords.
• Right-clicking on a line in the table will allow copying the displayed information (optional).
• Click the desired line to highlight.
• Click Remove to delete the password information. Do this for incoming and outgoing.

Stop and restart Thunderbird:

• Ask Thunderbird to get AT&T email.
• Thunderbird should ask for a password for the incoming server for which the password was just removed. Enter the secure mail key. Emails should begin downloading.
• Ask Thunderbird to send an email. Thunderbird should ask for a password for the outgoing server (can be the same password as for the incoming server).
• If emails begin downloading and sending, the problem is solved (You may now scream "Eureeka!").

Some things to note:

• Get one secure mail key for each AT&T email address.
• Secure mail key won’t affect your AT&T email password for the web site logon.
• Secure mail keys never expire.