Yahoo, which now does all the mail for Verizon and AOL as well as ATT require you to use oAuth authentication, or a mailkey.

Not being a verizon customer I can not tell you how to access your account with oAuth, Or perhaps Verizon can. Or point you to how to get a mail key.

Did this change very recently? I have other accounts that are not Verizon based that don't get their messages either. Thunderbird doesn't even ask for a login anymore. I think the issue is with Thunderbird, still. Is there a way to reset it to default settings?

The kicker is that no matter what email account I highlight and hit " Get messages " at the very bottom , it says it is connected to < the email account >

I've removed the remembered passwords and get the same result. It can not be connected, if it doesn't use a password.

Menu app icon > Help > Troubleshooting Information Under Application Basics' section locate - Profile Folder and click on 'Open Folder' close Thunderbird now. delete these files:

1. cert9.db
2. key4.db
3. logins.json

These will get created again after starting thunderbird.

Start Thunderbird.

Enter correct passwords at prompt and select checkbox to remember them so we be sure all is working correctly.

I hit this issue this morning with the update to 78.5.0 (32-bit).

I have one IMAP account, GMail, and two POP3 accounts.

The suggestion to delete

   cert9.db
   key4.db
   logins.json

allowed me to get my emails from GMail and from one of the POP3 accounts.

The other account doesn't prompt me for a password. I have closed TB and reopened it. I have told that account to "Get Messages". This account also does not appear in Activity Manager. There are two emails for this account sitting on the server. The account uses SSL/TLS and did before this update.

Deleting the files got mine going again! Yay.

Now, what did those files do? How would they get altered/damaged, so that getting files wouldn't work?

They hold your stored passwords and their encryption key While an update could have caused the issue I would be more inclined to say an attempted role back of an update or an anti virus product is likely at fault. But I am only guessing. Who lets the butter on the cupboard is essentially your question with about as many possible option as if you family had 8 kids.

wwtipton

re :I have told that account to "Get Messages". This account also does not appear in Activity Manager. There are two emails for this account sitting on the server. The account uses SSL/TLS and did before this update.

Did you update to 78.5.0 from a 68* version or from version 78.4.3 ? Do you get any error message for that pop account ? What server is that pop account? Yahoo, AOL, etc

Update History says my previous version was 68.12.1.

Note that this morning, GMail and Comcast, which were working after deleting the credentials, are broken again. I did verify that credentials for both were saved.

The third account is for my personal web site, notcomingsoon.com. I have sent a query to the host regarding the SSL/TLS version. I have not observed an error for this account or the others.

Thunderbird 78.5.0 update now I cannot download email, never asks for passwords...

Makes me VERY leery of ever updating Mozilla products again. Sheesh!

ddisandro This question has a 'Chosen solution'. Your comment does not say whether the 'Chosen Solution' worked for you or not. If it did not work for you then create your own new question.

However, currently - December 2020 If using ESET/NOD32 security/AV then probability is very high it is causing your problems. According to their forums, you should temporarily disable SSL until they solve the problem per https://support.eset.com/en/kb3126-disable-ssl-filtering-in-eset-windows-products?ref=esf - the problem is being reported by dozens of users https://forum.eset.com/topic/26517-problems-with-thunderbird-and-imaps/ https://forum.eset.com/discover/

FAO Toad-Hall I have this problem since about 2 Jan 2021. I have applied the "chosen solution" but it does not seem to solve it Log in OK. Receive pop-up messages notifying of new email OK. Can access incoming emails via webmail. Cannot access incoming emails dated after 25 Dec 2020 via Thunderbird, except for four emails out of a hundred or so! Have applied chosen solution. Files removed as directed. Log back in and two files (cert9 & key4) appear but not logins.json. Does not cure problem. When problem first aros (2 Jan 2021) I restarted Thunderbird. I did a complete virus scan with McAfee. Nothing found. I restarted my laptop. I reloaded Thunderbird. Now says update 76.8.0 (installed 15 Dec 2020!) Nothing made any difference. I'm using W10 on a Dell Inspiron 15 7000 2-in-1, wifi hu8, Plusnet (=British Telecom) ISP. Mike