hi, first thing is, please disable mail-protection related feature inside your AV/FW/SS software , especially those feature(s) which uses SSL/TLS proxy/gateway to scan malware inside emails. there are other solution than above to check for malware inside emails, which does not involve checking each data packets from mail-server, use those options. restart TB, and try again.

if above does not solve your problem , then please check out here, which option is valid for you, based on your choice of what you want to do.

AV = Anti-Virus . FW = Firewall . SS = Security-Suite . TB = Thunderbird.

atErik; this is too much for me.... 1st of all, I do not know which AV/SS settings that I need to change because my 68 was doing OK a few hours ago under these settings.... as for the other changes to make 78 work, I am sorry to say they are far beyond my capabilities.

I would like to try to get back to 68. Now I have another question: I had a TB profile backup copy that I made a month ago (Nov-2020). Since then I have used POP to retrieve/archive emails from Gmail..... is there a way, after I downgrade to my TB 68 (with Nov-2020 profile), that I can retrieve old emails (that I have retreived previously to TB) from Gmail again ?

PS: It is very very sad that TB becomes this bad..... I have been a TB user for zillion years, now I am at risk of losing all my archived emails from all those years.

Thank you for your help !

With due respect to atErik, going back to an older version is not for everyone, and in most cases should not be a first or even second option. So don't feel bad about not taking that advice.

The good news is the cause is UNLIKELY to be Thunderbird.

If you are using ESET/NOD32 security/AV then probability is high that ESET is causing your problems. According to ESET forums, you should temporarily disable SSL on ESET until they solve the problem per https://support.eset.com/en/kb3126-disable-ssl-filtering-in-eset-windows-products.

You might also inform ESET that they have broken your system. The problem is being reported by hundreds of users https://forum.eset.com/topic/26517-problems-with-thunderbird-and-imaps/ https://forum.eset.com/discover/

And failing that, the next points should be

• the question of who is your mail provider ?
• you should be looking at a KB articles like https://support.mozilla.org/en-US/kb/cannot-receive-messages

Dear Wayne; I am using Sophos Home. I cannot find any SSL settings that I can change. I was able to download my gmails from TB 68 a few hours ago before I upgraded to TB 78......

It is 1 of my 3 problems : the other problems being 78 cannot display my old messages from 68, and 78 cannot archive my sent emails (at least I cannot find the test emails).

You haven't answered this question "who is your mail provider ?"

"78 cannot display my old messages from 68" means what:

• you see no folders?
• you see no messages listed when clicking on a folder?
• you don't see the message CONTENT when clicking an item in the list of messages?

Hello; my email provider is GMAIL. I have attached a screenshot showing my TB screen. With 78, it cannot show anything except the 2 folders that I created today in 68 before the upgrade.

The bottom screenshot was the 78 message that I got after I sent some test emails (I was using my cable TV account to send emails out, not GMAIL). I cannot find any sent emails from 78. Everything is hidden ^_^.

Thank you for your help.

Start *Windows'* safe mode with networking enabled - win10 https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode

Still In Windows safe mode, start thunderbird in safe mode - https://support.mozilla.org/kb/safe-mode-thunderbird

Does problem go away?

can't recall which exact button can disable the "mail-protection" in Sophos-AV, but i used it earlier, it does do this SSL/TLS proxy/gateway based internet data packet inspection, that needs to be disabled. but may be this page is right, goto the shown webpage, and then follow that procedure to add your mail-server-addresses in the website/web-content EXCEPTION list, you may also have to add those mail-servers in more EXCEPTION list. More info on AV & TB.

i'm completely fine with whatever user chooses to do, as long as its helping the user.

TB = Thunderbird.

if you read it multiple times, perhaps then it would start to make sense to you, so don't give up. you can get second-TB (a v68 portable-thunderbird), and use old profile with it. make backup copy of entire TB "Profiles\" subfolder , before doing anything . in that way you have a backup copy of important things.

> it cannot show anything except the 2 folders that I created today in 68 before the upgrade.

Please be more specific. Perhaps a screen shot.

> i'm completely fine with whatever user chooses to do, as long as its helping the user.

reverting users to the previous version risks orphaning them on an older version, when in most cases the problem is isn't caused by TB, and is resolvable by other means.