The message that comes up is: Sending of password for user xxx did not succeed. Mail server pop.gmail.com responded: Temporary system problem. Please try again later.

Apparently a major bug in v. 78 of Thunderbird screwed up logging in to an IMAP server to receive e-mail. I have the same problem. I am trying to find a way to return to v. 68, which is still working on my other computer but is incompatible with v. 78 so you can't simply copy it over. Others seem to have the same problem in being unable to receive e-mail. Hopefully someone will provide a simple method of returning to the old version. This is a bad situation for many people.

Let's hope we can get a response - thank you Eric!

IF you have a working copy of the previous version of Thunderbird (v. 68) on another computer, here is how to revert back to it. I successfully completed this yesterday afternoon, after a couple of aggravating hours trying to figure out what was wrong, and then how to revert (I've got several Macs for different purposes, and luckily had upgraded Thunderbird on only one of them, albeit the most important desktop). If you just have the one computer and one copy of Thunderbird, unfortunately this won't help. I copied this from my original "I've got a problem" post elsewhere on this support page. A look at all the posts on this page shows that we've got lots of company, unfortunately.

"I just reverted to v.68 by copying a working version from my laptop MB Air to my desktop Mini (both running Mac OS 10.14.6). For those interested in reverting until all the bugs in 78 are fixed, just a couple of steps are involved. You must be copying from a working v.68 on another Mac. First, delete the application; I also deleted the dock icon just in case. Next on your destination computer, in user/library delete the Thunderbird folder (mine had 6 files in it). Your address book is in there so you won't get it back, you'll be substituting the version from v.68. Copy those two items (the Thunderbird v.68 application and Thunderbird folder from the user/library) from the other computer into the same respective locations in your destination computer. Thunderbird should launch and work properly (mine did after doing this, thank goodness)."

Thanks Eric - this looks complicated, but I'll do it as soon as possible. Thank you for your efforts and input, appreciate it! Rachel

I forgot to mention what should have been obvious - if you run regular backups (everyone should for situations just like this) you can retrieve a working version of Thunderbird from the backup.

Ahhh, that makes sense - thanks so much! Rachel

Hi rachel20, I tried another user svlad2009's suggestion to change the security.tls.version.min from the default value 3 to 1 in TB 78.2.2 and it worked, so I can download new emails again. This is actually the first time I to use the Config Editor in TB :) Here are the steps:

From the menu bar, select: Tools > Options. Under General tab, scroll to the bottom and select: Config Editor... then click I accept the risks! Search for the line "security.tls.version.min". Click or double click on this line and enter new integral value of 1 to replace default value of 3 (or 2) and click OK and close the box to complete. Then try to check your email again! Hopefully it will work for your too! Cheers!

Thanks for this suggestion anthony36, I tried this and it doesn't help :(. I was waiting for the second Thunderbird update for September which was this morning and it still doesn't work. Thanks for your efforts... I'm hesitant to do what Eric above, as I have quite a few mail accounts on my Thunderbird and am worried about how it will all be setup if I uninstall Thunderbird and install again...

If you change "security.tls.version.min" to 1 then also a restart TB might be required and this should work as a solution for not getting mails... Can you retry?