Thunderbird can't connect securely... because the site uses a security protocol which isn't enabled

Factual Questions
1

Thunderbird can’t connect securely to imap.gmail.com because the site uses a security protocol which isn’t enabled

I am getting this error message today, but I haven’t gotten it previously. The key point is I have changed absolutely no settings on Thunderbird or gmail.com for months. [And I get this message on other gmail.com accounts too.]

I use an old version of Thunderbird (2.0.0.24–newer version dropped an extension I liked)

Suggestions?

Thanks.

2

Thunderbird is Mozilla. We had this problem at my work a few years back - no mozilla browsers would show our website, because the org. we got our security certificate from was suddenly no longer good under the new security guidelines from Mozilla*, so the date on the certificate showed up as wrong, and got rejected by the browser.

So it’s not necessarily you that did sth., but could also be the site you’re connecting to has let their certificate lapse and now it’s no longer valid; or mozilla changed the rules.

  • In order to save money, we went with an org. that was free for certification, but with the new lines, mozilla only accepted paid org certificates, which we all found a bit strange from Mozilla, the freeware group.
3

Thanks.

After a few hours it started working again–with no setting changes.

4

So something at their end.

FYI “https” is actually a whole slew of different encryption systems under the hood. Some of the older ones are not real safe any more. So a thoroughly security-minded tech department switches off those old weak encryption flavors.

Meanwhile folks who only have older computers or apps that only understand the older flavors suddenly quit working when the site won’t use the old flavor and those clients’ apps doesn’t understand the new flavors.

So suddenly the lines at tech support go crazy and the business boss tells the tech boss: “Security, schemurity! We’re losing money; turn the unsafe useless encryption back on ASAP.”

I’d bet a buck that’s what happened to you. Whether it was deliberate or inadvertent at their end is a different question.

5

Gmail is currently set up where it will try to use TLS (the same encryption used by HTTPS), but, if that fails, fall back to unencrypted email. It would sound like it didn’t fall back to unencrypted email for you.

I can’t find any confirmation, but it’s likely that your older version of Thunderbird doesn’t support the version of TLS needed by Gmail. So you are likely exchanging emails in unencrypted.

Since I see no indication of Google changing this policy, it was probably a one off event, maybe even an experiment to see how many people it would affect if they forced you to use encryption.

I do hope you have checked to see if the extension you have or an equivalent exists that will work on a newer version of Thunderbird. Your version is over 7 years old at this point.