You do have to use a secure mail key in TB in place of the account password, and a separate key is required for each computer that has the account. Server settings etc. are here:

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

sfhowes, Yep, those are the default settings that Thunderbird is coming up with, but even using my brand new, shiny, hot-off-the-press secure mail key from earlier this afternoon, it still doesn't work. (I just tried again.)

And that leaves begging the question as to why/how my Windows 10 machine works just fine with smtp.att.yahoo.com for outgoing. Mind you, I'm not going to argue with a machine that's working--far from it--but it doesn't agree with the official settings.

It would help if I just knew *what* the confusticated thing wants! This 'Probably wrong configuration, username, or password' thing is useless. Might as well say someone died because his heart failed, or he had a stroke, or he had cancer, or he bled to death, or...well thanks, but it hardly clarifies matters. As far as I can tell, I've done everything right, except that obviously I haven't, which is a wee bit frustrating.

Where do I go from here? There's only email address, password, and settings, and I've tried all the permutations I can think of. Although I've already tried it and it didn't work, is there any benefit to typing out the random character string behind the secure mail key or is the mail key itself the preferred way?

I'm at a total loss, here. This is supposed to be simple and automatic and all, but it's not working.

Thanks, Grey

You do have to use a secure mail key in TB in place of the account password, and a separate key is required for each computer that has the account.

You glossed over this part of the reply, do you have a mailkey as required by your mail provider? https://www.att.com/support/article/email-support/KM1240308/

Matt, I fail to see what I glossed over. About half-way down my original post I said:

"--I generate a fresh secure mail key in case the silly things have a shelf life. The new one doesn't work, nor does its random character string."

Then in my previous reply, I said:

"...but even using my brand new, shiny, hot-off-the-press secure mail key from earlier this afternoon, it still doesn't work."

What am I missing?

Thanks, Grey

Please check the following: On new computer: Firewall Access Firewall (might be controlled by default Windows or an Anti-Virus you installed). Make sure Thunderbird (thunderbird.exe) is set up as an allowed program.

VPN Check computer for a VPN. Some Anti-Virus products now offer VPN and have a habit of auto enabling it. Switch off VPN.

ATT can get access via yahoo or ATT server settings.

If account is created but not working then please check the saved passwords. You may need to 'Edit' a saved password and replace with secure mail key. Settings > Privacy & Security click on Saved Passwords click on 'Show Passwords' If Windows security window requests password then it's the one you use when you start up computer and logon to see desktop. Right click on each line (whether it's mailbox:// or imap:// and the smtp://) and select 'Edit Password' Completely clear content and enter the secure mail key. click on 'Close'

If using the ATT server: info: https://www.att.com/support/article/email-support/KM1010523/ Note: POP incoming and outgoing is different from IMAP

POP:

• Server name: inbound.att.net
• Port: 995
• Connection SEcurity: SSL/TLS
• Authentication Method: Normal Password
• username: full email address
• Password: secure mail key

SMTP:

• Server name: outbound.att.net
• Port: 465
• Connection SEcurity: SSL/TLS
• Authentication Method: Normal Password
• username: full email address
• Password: secure mail key

This for IMAP IMAP

• Server name: imap.mail.att.net
• Port: 993
• Connection SEcurity: SSL/TLS
• Authentication Method: Normal Password
• username: full email address
• Password: secure mail key

SMTP:

• Server name: smtp.mail.att.net
• Port: 587
• Connection SEcurity: STARTTLS
• Authentication Method: Normal Password
• username: full email address
• Password: secure mail key

re : secure mail key: https://www.att.com/support/article/email-support/KM1240308/

Toad-Hall, --Firewall--This sounds promising, but Thunderbird is not listed there, nor is Mozilla. Firefox is listed (Firefox and Firefox (C:\Program Files\Mozilla Firefox) and it works just peachy. --I'm using Windows Defender. No other anti-virus programs. No VPN. --Per above posts, I've left Thunderbird defaults as-is...so: Incoming server is POP3, everything is as per spec, except there's no field for "Password: secure mail key" Outgoing server is as per spec, except there's no field for "Password: secure mail key" Unless I'm missing something, IMAP is out of the equation if I'm using the above, yes? POP has worked fine on my Windows 10 PC, so was figuring that I'd set the new PC up the same way.

...okay, this is weird...I had the window for Windows Defender Firewall\Allowed apps open (Thunderbird not available, as noted above) and the button for "Allow another app..." was grayed out. I looked at something else, typed some here, then looked back at that window and the Allow button was live. Hmmm... I clicked it. Thunderbird is not listed on the "Add an app" window (nothing is) and is not available under Browse, either as Thunderbird or Mozilla. (Path = C:\Windows\System32...the default path...I did not go hunting), so I can't find a way to add Thunderbird manually.

--"Notify me when Windows Defender Firewall blocks an app" is checked. At no point have I seen a notification about anything being blocked.

Have I mentioned how much I hate Windows 11? (I saw something on Slashdot that said that 11 was on the verge of overtaking 10 for market share...but only because Microsoft was forcing the switchover.) I've now wasted over another hour on this and I'm not getting anywhere.

Thanks, Grey

Toad-Hall, Apologies...I forgot to respond to part of your post. I was unable to find anything in Thunderbird called Settings/Privacy & Security/Saved Passwords. Searching for "saved passwords" brought up a popup called Saved Logins does not show any accounts/passwords at all, so there's nothing to be edited.

Thanks, Grey

re :Incoming server is POP3, everything is as per spec, except there's no field for "Password: secure mail key"

I think you may have misunderstood. The 'Server Setting' for 'Authentication Method' must be set using the option 'Normal Password'. That goes for both incoming and outgoing smtp.

But when asked for actual password when creating account you must enter the 'secure mail key' instead and make sure to select the checkbox to remember password.

Please confirm you got the 'secure mail key' via the ATT webmail account - not the yahoo logon. re : secure mail key: https://www.att.com/support/article/email-support/KM1240308/

If you downloaded Thundebird from the official Thunderbird website: https://www.thunderbird.net/en-US/thunderbird/all/

Then Thunderbird should get installed in either of the following locations:

C:\Program Files\Mozilla Thunderbird\thunderbird.exe OR C:\Program Files (x 86)\Mozilla Thunderbird\thunderbird.exe

But if you got a download install from the Windows App Store then nothing is quite so simple. C:\Program Files\WindowsApps\Mozilla Thunderbird\thunderbird.exe

But the 'WindowsApps' folder is hidden so you will need to go to view>show>Hidden items I would not have thought Windows OS would auto block anything if used from the AppStore.

Unfortunately, if you use install from WindowsAppStore then all the profiles data will also be in a completely different location. This has caused some people a real headache.

Toad-Hall, Per 4/7/25 @ 7:50 AM When you said "Authentication Method: Normal password," followed by "Password: secure mail key," I took you literally--that there would be two separate fields within the Incoming and Outgoing fields. In any event, assuming that by "Password" you mean the password entry field in the top third of the Manual configuration window, under "Your full name" and "Email address," then, yes, I used my secure mail key.

Yes, Authentication method for both incoming and outgoing = Normal password. That's the way it defaults and you have indicated that the defaults should work.

Yes, my secure mail key came from ATT, fresh as of 4/4/25.

Per 4/7/25 @ 8:33 AM This copy of Thunderbird came from Mozilla. I have confirmed that it is in C:\Program Files (not C:\Program Files (x86)).

The program seems to run okay...so far as it goes. There's an icon on my desktop. When I double click it, it attempts to initiate the setup process, but fails. At this time, I am leaving all configuration details at the default values. I've got the Manual configuration open to confirm that the fields are what they're supposed to be, but am not changing anything. You guys seem to feel that the defaults are what they need to be and they agree with what ATT says. That still doesn't answer why Thunderbird on my Windows 10 PC has a different configuration--and works just fine--but maybe it's something to do with Windows 10 vs. Windows 11...? I don't know. You guys are the experts.

Thanks, Grey

re :This copy of Thunderbird came from Mozilla. I have confirmed that it is in C:\Program Files (not C:\Program Files (x86)).

Firewall Exit Thunderbird Access Firewall Set up the following as an allowed programs:

• C://Program Files/Mozilla Thunderbird/thunderbird.exe
• C://Program Files/Mozilla Thunderbird/updater.exe

In Windows Defender Firewall\Allowed apps click on button for "Allow another app..." clickon 'Browse' You have to look for this: 'C:/ Program Files' then locate 'Mozilla Thunderbird'

First please make sure the Firewall is not being a pain because if it's blocking Thunderbird then it will not matter whatever server setting you use. You really do need to get it set up to allow Thunderbird and the Thunderbird updater as this will allow the necessary ports to operate as expected.

Just in case you were not aware of it - Windows 11 also has a new feature 'Smart App Control' https://support.microsoft.com/en-gb/windows/app-browser-control-in-the-windows-security-app-8f68fb65-ebb4-3cfb-4bd7-ef0f376f3dc3#bkmk_smart-app-control

re :That still doesn't answer why Thunderbird on my Windows 10 PC has a different configuration--and works just fine

ATT use yahoo servers. They set everything up so people could use the yahoo server settings for att or Att server settings. That means you can use the same as on Windows 10 machine if you want to. It really should not matter what server settings are used whether it's the ATT or the Yahoo-ATT.

You would need to start to create the account and then after clicking on 'Continue' look for a button 'Manually Configure' which you can then use to alter the server name for incoming and outgoing. But make sure you are using the correct Protocol for the correct settings. Example: If you have selected Protocol is IMAP and then use Pop server settings - it will not work.

The yahoo att server settings: POP Incoming mail server: pop.att.yahoo.com

IMAP Incoming server name: imap.mail.att.net

Outgoing mail server (SMTP): Server name: smtp.att.yahoo.com

All other settings eg: Port etc would be the same, but you may need to access the webmail account on the yahoo login website and Generate App Password via that login to use instead of password in Thunderbird.

• https://help.yahoo.com/kb/generate-manage-rd-party-passwords-sln15241.html

Toad-Hall, I managed to add Thunderbird & Updater to the Firewall exceptions. Last time it was grayed out and wouldn't listen to reason. This time it worked. (I hate Windows 11...or have I said that before? Computers ought to at least be consistent.) Being superstitious, I verified that both were in the list. In both cases, they were there and checked for Public. I tried installing Thunderbird. It failed. I checked Private and tried again. It failed again. This is with all defaults as far as Thunderbird thinks things should be done. All I did was add my email address and secure mail key (the newer one from the other day).

I pulled up Smart App Control. It says it's Off. "If Smart App Control is off it can't be turned on without reinstalling Windows." I've never heard of it and am not clear what it does. Microsoft's explanation of what it actually is doesn't say diddly-squat. It's like listening to certain politicians speak. Lotsa words. No semantic content.

As far as which servers and all...I don't care as long as it works. Unfortunately, the 'as long as it works' part of the equation seems to be missing and I don't know what to do. The number of hours I have put into this is getting waaay stupid. I'm a single parent and about a bazillion other things and this is taking a huge amount of time that I can ill afford. I've already fallen out of an online class I was taking via MITx and that's kinda making me a bit grumpy. I needed my time so as to keep up with classwork and it's frittering away, away, away...

Thanks, Grey