and is your wide using oAth2.0 and you are using password for connection perhaps? That is the most common cause of yahoo failure these days as they are progressively withdrawing the use of passwords (other than app passwords) for retrieving pop mail.

Hi Matt, Thank you for getting back to me so quickly. No, both of us are still using Normal Password for Yahoo. I haven't change yet. Was waiting to make sure issues with the change were identified before creating a problem. I guess I could give it a try. Any idea how I can change this TLS security setting? I have no idea where it's located or how to change it. I'll get back to you if I decide to move forward with the oAthu2.0.

Thanks, Dennis

Maybe you can try to generate an app password to use it on TB till you're moving to oAthu2.0? You can check the details from here https://support.mozilla.org/en-US/questions/1304518#answer-1349911 with some instructions mentioned by yahoo

> After messing around in Account Settings I was able to get my messages by changing my Security Setting from TLS/SSL to None in Account Settings.

see https://bugzilla.mozilla.org/show_bug.cgi?id=1662799#c2

Hi Everyone,

Thank you All for your responses!! Very much appreciated. I just wanted to give you all an update and see if you might have some suggestions. I'm using Avast Antivirus Free. If I turn off the Email Core in Avast, I can keep my Thunderbird security setting to SSL/TLS and receive emails with no problem. However, now I don't have virus checking my incoming emails. So, as you can see I'm in a catch 22 situation. Any ideas, would be greatly appreciated. I did contact Avast my email to see if they have a solution. I'm going to keep my Thunderbird security settings at SSL/TLS and turn off Avast Email Core for now.

Looking forward to some ideas and solutions!

Thanks,

Dennis

Hi Everyone, If I turn off the Email Core in Avast, I can keep my Thunderbird security setting to SSL/TLS and receive emails with no problem.

So you have a problem with avast. Have you contacted them? If not I suggest you do.

However, now I don't have virus checking my incoming emails.

Neiter do I. It is one hurdle to many ion my personal opinion.

So, as you can see I'm in a catch 22 situation. Any ideas, would be greatly appreciated. I did contact Avast my email to see if they have a solution. I'm going to keep my Thunderbird security settings at SSL/TLS and turn off Avast Email Core for now.

Lets look at the risks this magical email scanning is saving you from. You get a text file off the internet (that is what an email is) Some product scans it to make sure it is not a threat. A threat in a text file. not going to be doing much and very hard to infect a computer with as text file only contain text, the do not run and they are not programs.

So Thunderbrd stores this file. It is still text and even if it contains an attachment with a virus, it is in text form so it can not run.

You open the file. Thunderbird looks at the body, which is usually HTML and renders the body. Thunderbird does not support scripting of any kind, so about the greatest risk of opening a HTML document is it might also download a picture from the internet that informs the sender you have read the email. (Look up webbug for more on that.)

You open the attachment. So thunderbird converts the attachment from text into it's original form, be is an image or a document. While this is going on in memory, the anti virus you are using has an opportunity to scan the memory for a virus.

Then Thunderbird write the new file into the temp folder on your computer. Again when this file is created your anti virus has a chance to scan the file Then Thunderbird passes the file name off to windows and asks it to open the helper that read this type of file, be is pint, word or a PDF viewer. The helper application is launched with a command to open the temp file. when the program attempts to open the file the anti virus again gets a chance to scan the file before it is loaded.

What I think I am saying is I think email scanning if something of a farce that can best be considered "another" line of defense. Given that Thunderbird does not run scripts and the anti virus has three other chances to scan attachments before they are actually "opened" having a fourth does not do much for me.

Hi Matt, Thanks for you helpful feedback! You've convinced me that I don't have a real problem by not having Avast scan secure sites. Right now, everything is working just fine so I'm not going to upset the apple cart so to speak.:-) My next adventure will be the changing of Security setting for Thunderbird from SSL/TSL to oAthur2 per Yahoo's new security announcement. Have to do that before Oct 20th. Todd-Hall, has given me the method to follow so hopefully, I won't run into a password issue and loose all my folders and address book. Thanks again and I appreciate your feedback! Dennis

Just keep in mind, SSL/TLS is not the setting. The authentication method is. You change normal password authentication method to oAuth2 and under no circumstances remove your account like Yahoo tells you to. That method simply looses all your currently downloaded mail. Not what most folks are wanting.

Hey Matt,

Thanks for the reminder. Yes, I'm following Todd_Hall's recommendations, which as you mentioned, is not to remove my account. The process is to make sure Thunderbird is set up to receive cookies. The change both pop mail and smtp mail to oAuth2 and then click Ok and get out of Thunderbird. Wait awhile and then reopen Thunderbird. I assume I'll get some question about who am, and then proceed to let me access my mail. At that point all my folders and emails should be there. If I'm wrong here, please let me know quickly.

Thanks,

Dennis

You certainly will get prompts. they will appear as web browser windows asking for your whole set of yahoo credentials, from user name and password to the types of information Thunderbird is asking to access. Mail and Contact IIRC, but there may be other things yahoo link in with that. Just be sure to say yes to the permissions. Saying no kills it dead in it's tracks. SO while you ask notified, not allowing any of it is not an option.