I manually upgraded one of my 68.10 installations to 78.0 (silly me, although there's nothing overt that warns against it). It mostly works, except for one POP3 account (top of the account list) stopped being able to update - just timed out. Two other POP3, including Gmail continued to work, as does the IMAP account. Tried all kinds of tricks - deleting account in saved authentication, various secure authentication, etc. - nothing secure worked.

I was able to get the first POP account working by downgrading authentication security to old "none" (port 110) from SSL/TLS. But, I wasn't happy doing it. Also, most of the e-mail providers won't allow that anymore.

I reverted back to TB 68.11 (updated since I changed from 68.10), and ran the "allow downgrade" command on the profile at startup (see elsewhere) but didn't create a new profile. Calendar data appears to be gone (honestly, it may have been gone on the 78 upgrade - didn't notice because of the POP3 issue). However, all accounts are back to working normally with SSL/TLS.

Curious about the broad and varied POP and IMAP authentication problems with 78 - I've seen some rough times with Firefox and TB upgrades over the years, but this is one of the one of the more perplexing ones.

Try to change in THUNDERBIRD preferences editor security.tls.version.min from 3 to 1

From the menu at the top right, go to Options. Scroll all the way to the bottom and click on Config Editor. Skip past the warning. Scroll down until you find security.tls.version.min (or paste security.tls.version.min to upper frame) Double click on it, and set the value to 1

Mozilla disabled TLS 1.0 and 1.1 in the latest versions of Firefox and Thunderbird. Thunderbird 73b and above. This causes issues with anyone connecting via SSL/TLS/StartTLS to services uses 1.1.

Belated thanks. This makes sense. My ISP mail provider needs a little kick in the shorts to upgrade their TLS, I guess.

Best Regards

Hi kotouc74

Done what you suggested but still no connection to my accounts. Any other suggestions? Thanks

Doesn't help with OP problem, but the locked envelope icon next to the account name represents a secure connection has been defined, not that there is a problem with the account.

Ah...Thanks krj that's interesting......but as you say, it doesn't help my problem. Anyone else got any suggestions????

re:On the 21st July Thunderbird updated. I'm presuming it updated from 68* to 78*.

Thunderbird has switched off all auto updates, so if using a 68* version if should only update to next 68 version not update to 78. So to use 78*, you would have had to uninstall 68* and then manually download and install 78*.

If it really did do an auto update from 68 to 78, then you have other Updater Software on your computer that program caused an update. I strongly advise you do not allow other Updater Software to look for Thunderbird updates because the current release on website eg: 78* is not the correct releases for 68* eg: 68.11.0 should update to 68.12.0 not 78* but the 'Updater software' is not aware of this and Thunderbird does know about it.

re :not been able to get or send emails on any accounts

You mention gmail, but what other servers are you using? Info supplied by kotouc74 will not effect any gmail account. It only effects those servers still using older TLS.

If nothing is coming in or going out on several accounts on different servers then you need to check the Firewall and make sure Thunderbird is an allowed program. Exit Thunderbird. Sometimes the Firewall might think this updated Thunderbird is a new program and not recognise it. So access Firewall and set Thunderbird as not allowed and ok it, then go back and reset to be allowed and ok it. Note: the Firewall maybe part of your Anti-Virus Program.

Thanks Toad Hall......I do indeed have Thunderbird 78.2.1 So tried unistalling 78 and installing 68 but can't find a link to 68 on the website. It only offers 78. Suggestions please?

Ever since the change from 60* to 68* Thunderbird has been using one profile per installation and this means it is not as easy to go back to a previous version.

In addition, when you updated to 78, all the address books had the format converted from .mab files to .sqlite files.

Uninstall 78 Download 68.12.0 from link:

• http://ftp.mozilla.org/pub/thunderbird/releases/68.12.0/win64/

You need to select your chosen language eg: en-GB is English British Then click on the 'Thunderbird Setup 68.12.0.exe' link to download. run installation, but do not launch Thunderbird.

Instead start Thunderbird this way: Downgrade protection can be overridden by launching Thunderbird through the command line with the --allow-downgrade parameter.

• in Windows search type: Run
• Select the Run.app
• Type: thunderbird.exe -P --allow-downgrade

Note: after the .exe there is a space then -P then a space followed by the rest no spaces.

• click on OK

This should launch the Profile Manager allowing you to select the correct profile and start Thunderbird.

Hi Toad Hall I just wanted to "Thanks a million"........the problem was driving me mad, and I haven't be able to find a program as good as Thunderbird! Thanks again Gerry

@Toad Hall

Worked like a charm. MASSIVE kudos.

I had different problems from the o.p: for instance writing e-mails only showed space for one recipient; Signal Spam extension disallowed, &c. So very grateful.

Note: have changed handle to ardj, but Mozilla slow to pick that up.