you would be about ATT customer 20 here with this issue. Apparently you need to go to the ATT web site. Create a new mailkey as required by ATT I think ever since the sugned up with Yahoo to deliver mail, and use that in Thunderbird instead of your password.

Sorry to have been so awkward navigating Thunderbird help. I am pleased to find a place to reply.

But the problem of not being able to download from att to Thunderbird persists. I notice that some miracle happened last November and people started receiving their mail. I have scoured that thread for something to do. My windows 11 and windows defender are up to date. I will try moving items out of inbox and back in but that did not sound like a permanent fix. I'm on my second secure mall key. I've tried closing down after making it and before going to TB. I checked all the settings by initiating a new account. POP 3 was the recommendation but there doesn't seem to be a way to change POP to POP 3 on the accounts page. That was the only variable I could find. (The ATT lady of Thursday had me switching from IMAP to POP and back.)

Suggestions gladly received.

Have you replaced the mailkey stored as your password in Thunderbird with a new one?

https://support.mozilla.org/en-US/kb/password-manager-remember-delete-change-tb

I have manually entered the new mail key when asked for my password in both sending and receiving. (They had been saved by password manager earlier) Still no mail. The odd thing is I think (at this point I'm insecure) that when this started I checked my password and it was the old system password. I think I don't understand the relation of these passwords.

On Sunday June 30 I went to ATT, removed all my old mail keys, created a new one, shut down, opened and opened Thunderbird, when I could enter my new key, my mail downloaded. It worked for about 24 hours and then stopped. I went through the whole ritual again but the new mail key was refused.

Any more ideas? Anything.

So far, we don't even know if you're using the correct settings, or what has been done switching back and forth between POP and IMAP (which is more involved than just changing existing settings). Post your Account Settings/Server Settings, including Server Type.

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

Thank for paying attention. At this point your message and two others have been downloaded to Thunderbird but nothing can get sent but is refused. Screen shot does not seem to work on this computer so I will have to copy out the settings. ATT actually dictated them to me about a week ago but they were what was in the machine.

Inbound: POP inbound.att.net Port 995 SSL/TLS Normal password

Outgoing SMTP .att.net - outbound.att.net

That dot before att.net in outbound seems a bit strange. Thank you for your patience. Marjorie

found I could scroll down further to outbound at Port 465

I am follow two different sets of instructions for a screen shot but nothing emerges

To make screenshots, use the built-in Snipping Tool (Ctrl+Shift+S). Also, state the Server Type.

Got OIT where I taught to help me with screen shots. The whole process, all the steps, are not obvious to a naive. I'll try to copy. I think the server information is here. If not tell me what I need to look for. Thanks for understanding.

The settings look correct (the Description field can be anything, as it doesn't affect sending). I've no idea why it works for a while and then stops. Check that your security/AV app isn't managing TB passwords.

If new mail is arriving in the Inbox, as viewed in webmail, but not in TB, it could be as simple as there being a corrupted message blocking downloads to TB.

Since the new mail key of a few days ago, my email has been downloading. The problem is that I cannot send anything. This is why I asked about the addresses that att dictated to me for sending.

Security/AV as managing TB passwords?  I have been into settings  and security/anti-virus  but do not know where to look to figure out if there were a block.  Sorry to provide you with such problems.

What is the antivirus? It might be blocking sending unless you disable scanning of outgoing mail, which is the general recommendation.

IMy anti-virus is microsoft defender. Why would it suddenly block ? The mail key seems to have solved the incoming. I went to settings and to the anti virus but am not sure of the next move. The layers are microsoft defender; virus and threat protection settings; manage settings,; exclusions. the dot before the address doesn't mean anything?

Just checked the password again and it is entered correctly. However I am having a bizarre time when I try to send. Enter a password, ok but before I can finish it another little window pops up asking for a password. I had about six of these earlier today. I'm still wondering about that .net for outgoing but it is not in the bolded part of the out going address.

When you say 'password' for the outgoing, are you entering the same secure key used for the incoming?

Yes, not OK?

The same secure key must be applied to incoming and outgoing servers.

Same key has been applied. I have checked it several times. I can't figure out why I am constantly asked to re-enter it in outgoing. It never seems to finish being accepted.

I still wonder about that outgoing address .net

After once more checking that the proper passwords were entered last week, I decided to give up over the weekend. On Monday I sent myself a test message from Thunderbird. Not only did it send but everything else since then has sent. I am still filled with trepidation but also relief. I will always wonder what happened. Thank you for your attention. I did not feel totally alone in an electronic slog.