Thunderbird uses most current version. I do recall people getting notices that some email clients may not be current and they listed Thunderbird in that list, but they did not say Thunderbird was back level. That particular provider was mail.com. If you do have a message that states Thunderbird is not current, we would appreciate receiving a copy so we can advise that organization. Thanks for writing.

from https://www.thunderbird.net/thunderbird/78.0/releasenotes/ (released back on July 17, 2020)

TLS 1.0 and 1.1 disabled

Which means Thunderbird Releases (since Tb 78.0) supports TLS 1.2 at minimum, including TLS 1.3

https://support.mozilla.org/en-US/kb/thunderbird-78-faq

Seen comments that mail .com may be making email client users have to upgrade their account to a Premium account in order to get email with email clients like Thunderbird like in /questions/1389093#answer-1535224

David: It is mail.com sending out the message. I got the message on 9/12. This was before I received the upgrade notice on Thunderbird. I don't remember what version I had prior but I believe it was in the 98 series version. After I got the notice from mail.com it was shortly thereafter I got the notice from Thunderbird to download the new 102 version since it needed manual install, which I did. I have the message from mail.com, do you want me to post it here or email it?

No need to send it. That message was poorly worded and left many users posting here out of concern. They could have saved a lot of grief had they researched more thoroughly.

help

Disabling TLS 1.0/1.1 for POP3 and IMAP4 on December 01, 2022

Starting on December 01, 2022, Office 365 will begin retiring Transport Layer Security (TLS) 1.0 and 1.1 for POP3 and IMAP4. TLS is a standard protocol used to provide secure web communications for POP3 and IMAP4. POP3 and IMAP4 are the client/server protocols for receiving emails. We will enforce TLS 1.2 moving forward to provide enhanced encryption and help ensure your emails are received more securely. We have already disabled TLS 1.0 and 1.1 for most Microsoft 365 services in the worldwide environment.

When this will happen

December 01, 2022

What do I need to do?

Our records show that your email account has recently been accessed with POP3/IMAP4 through TLS 1.0 or 1.1. POP3 and IMAP4 will not be able to connect with TLS 1.0 and 1.1 starting on December 01, 2022. You will not be able to receive emails with POP3/IMAP4 protocol after that. To continue accessing your email account using POP3 or IMAP4, please upgrade/update your client to support TLS 1.2. Your emails will not be removed, but you cannot access them without upgrading your client. You can find out technical details on how to upgrade in this article: Disabling TLS 1.0 and 1.1 for Microsoft 365 - Microsoft Purview (compliance) | Microsoft Docs

What if I cannot update/upgrade?

If you cannot update/upgrade your legacy client, we provide an opt-in endpoint for you to continue connecting with TLS 1.0/1.1. Your legacy clients must be configured to pop-legacy.office365.com for POP3 and imap-legacy.office365.com for IMAP4. Using legacy versions of TLS is not as secure as TLS 1.2, however, so we recommend you update and use TLS 1.2.

I don't see what I posted

got email from microsoft to update TLS - is this a problem?

I am using a beta version - 107.0b4

The TLS version is not shown, but is the beta is not 'safer' than the release version and (in my opinion) more subject to problems. Anyway, I don't think you're susceptible to any TLS issues.

got email from microsoft to update TLS - is this a problem?

Nothing to update with TLS. Thunderbird supports TLS 1.2 at minimum, including TLS 1.3 as I posted in my reply above.

The TLS version is not shown, but is the beta is not 'safer' than the release version and (in my opinion) more subject to problems. Anyway, I don't think you're susceptible to any TLS issues.

I put Beta on long ago when I took over this machine 5 years ago - it was easier at the time - should I go with regular? at that time my brain worked better than now -

susan_nett said

got email from microsoft to update TLS - is this a problem?

Nothing to update with TLS. Thunderbird supports TLS 1.2 at minimum, including TLS 1.3 as I posted in my reply above.

so far it has come on 2 email accounts I rarely use