Outgoing e-mail to att.net fails with latest Secure Mail Key using Thunderbird version 102.4.1 (64-bit). When I was using a much older version of Thunderbird, the Secure Mail Key (#1) worked fine for both Get Message and Send. Upgrading to a more recent version of Thunderbird caused both Get Message and Send to seem to timeout with no error message and when I would try again, Thunderbird would prompt me for the password. I had to re-enter the Secure Mail Key #1 manually, but this produced the same results. I went to att.net and created a new Secure Mail Key (#2). I used this as my Get Message password and it worked, but Send still failed. After a Send failure, Get Message also failed. I went to att.net again and created a new Secure Mail Key (#3) and using this as my Get Message password worked and I checked the box to "Use Password Manager to remember this password", but Send still failed. Get Message still works while Thunderbird was still active. If I exited from Thunderbird and started it again, it would prompt me for the password again as if its Password Manager wasn't working. I re-entered Secure Mail Key (#3) and checked the "remember" box again, but NOTHING happened. When I clicked on "Get Message" it prompted me again for the password. I re-entered Secure Mail Key (#3) and checked the "remember" box again, and at the bottom of Thunderbird's window it displayed "host contacted, sending login". This continued to display for more than a minute, but then this went away with no further information shown -- as if it had timed out. Normally, it would have shown the number of messages received or would have displayed "No new messages found" (or words to that effect). If I click on Get Messages again, it prompts me for the password again. So the bottom line is that doing a Send results in a failure that causes all subsequent Get Messages to also fail. It's not clear why "Use Password Manager to remember this password" doesn't seem to be working, unless any login failure (Send or Get Message) resets the "remember" flag in Thunderbird. I've done a chat with AT&T and they claim that it's a problem with Thunderbird. My outgoing server (SMTP) settings are set to "AT&T - outbound.att.net (Default)" using port 465, the user name is my e-mail address at att.net, other settings are normal password, SSL/TSL. This has never changed.