Do you have an antivirus scanning incoming mail? If so disable that functionality and try again. POP mail and antivirus is all good, until a malformed mail the antivirus can not cope with pops up and the antivirus just drops dead in it's tracks and no mail comes in, or the same partial list of outstanding mail downloads over and over and it stops when it get to the malformed mail each time.

Personally I use windows defender. It does not mess with mail and life is so much simpler.

Thanks for your reply, Matt.

Although I generally run an anti-virus program, I am not currently subscribing to any. That being said, I do have Windows Defender turned on. The only other thing that could possibly get in the way is I run Nord VPN. That runs constantly, until I have a problem (mostly that a small number of websites don't allow me to connect with a VPN running). I have turned that off and on multiple times, and even restarted my laptop in between on some of those times, but I still have the same results... one yahoo acct continues to download mail from yahoo into Thunderbird, while the other does not.

FYI... I also have five gmail accounts and one AOL account being downloaded into Thunderbird and none of those are affected either. They all continue to retrieve mail and load into Thunderbird.

Any other suggestions would be appreciated.

Thanks, Lew

you can probably also add yahoo to that small number of websites you speak of and google as well as far as gmail goes. Most email providers are very concerned about hacking and users loosing control of their accounts so almost all of the large providers will give you some for of grief if you use a VPN, from frequent requests that you re-authenticate to outright just refusing connections.

Most VPN products have specific steps you have to take to use a mail client with them and some simply do not support email at all.

Yahoo are probably basing your location on the location of your phone. so when you connect from somewhere else they get suspicious, when you connect potentially from two other locations to where 6our phone is they just go not on my watch.

• Start Windows in safe mode with networking enabled - https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode
• Still In Windows safe mode, start Thunderbird in Troubleshoot Mode - https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird

Does problem change?

Wayne,

I tried to do what you have suggested. The first link states that you have to be in Recovery Environment in order to get to Safe Mode. I went to the link for RE and followed the instructions, but it is asking for a Bitlocker key, which I don't have. I cannot get passed that so apparently I can't get to Safe Mode so I can't test to see if the problem still exists in Safe Mode.

I did, however... just for the heck of it, start Thunderbird in Safe Mode and checked for new mail for the account in question. It gave me all the normal messages... sent login info, checking inbox, there are no new messages.

Thanks, Lew

Matt,

I mentioned that some (a small number of) websites don't let me get to them while the VPN is on, but I don't have a problem getting my mail with the VPN running. Yes, my VPN makes it look like I am logging on from a different place than I am actually located, but since yahoo lets me logon to download mail from one account and mail doesn't download from another yahoo account, I'm guessing it is not the VPN that is the problem.

Also, when the mail is checked, both of those accounts give me the messages that the login info has been sent, checking the inbox, then the one account downloads whatever is there and the other says no new messages to download even when there is new mail. It is apparently logging into the account, but something is making it think that the new mail is not there.

One more thing... I just tried sending mail from Thunderbird from the account that is not downloading. The email was sent to both of those yahoo accounts. It downloaded successfully to the account that is working properly, but not to the other. When I looked at that account in the browser the email was there. I tried checking for new mail again and got the same thing... no new mail to download.

So, apparently, I can still send mail from that account, but I still cannot download mail to Thunderbird from that one.

Regards, Lew