This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Lost connection to email host, Thunderbird 78/Win10

  • 6 replies
  • 1 has this problem
  • 8 views
  • Last reply by John

more options

I'm running Win10 and TB ver. 78, recently updated. I am no longer able to receive or send emails. When I logon, nothing happens, and when I try to send a test message, I get this msg:

"Sending of the message failed. Peer’s certificate has an invalid signature. The configuration related to xxxxxxx.com must be corrected".

I have contacted the email hosting service regarding this error message, they swear it ain't them, and the interesting part is that I'm able to receive and send emails from my hand phone. From this, I conclude that the problem must reside with TB, maybe there's a problem with Ver. 78??

I'm not a computer buff and will be grateful for any help.

Thank you in anticipation.

I'm running Win10 and TB ver. 78, recently updated. I am no longer able to receive or send emails. When I logon, nothing happens, and when I try to send a test message, I get this msg: "Sending of the message failed. Peer’s certificate has an invalid signature. The configuration related to xxxxxxx.com must be corrected". I have contacted the email hosting service regarding this error message, they swear it ain't them, and the interesting part is that I'm able to receive and send emails from my hand phone. From this, I conclude that the problem must reside with TB, maybe there's a problem with Ver. 78?? I'm not a computer buff and will be grateful for any help. Thank you in anticipation.

All Replies (6)

more options
more options

Thanks for your help. I checked with the (paid) hosting service provider. They confirm their security protocols are up to date, and they are unable to help, view Thunderbird being 3rd party software. I have checked and double-checked server settings, and they are correct. I can solve the problem, I guess, by a fresh installation of Thunderbird on another laptop if I could work out how to transfer the Mail and Archive folder from the faulty Thunderbird installation to a new one.

more options

re :They confirm their security protocols are up to date.

Have you tried changing the minimum security level to 1 and restarting Thunderbird or not ? because they might be using most up to date protocol for the webmail but not necessarilly for the imap, pop and smtp. You are using third party so they are not exactly interested.

I really suggest you try it first. After all you can easily change it back. Others with same error as you have reported that the following worked.

Menu app icon > Options Select 'General' Scroll to bottom. Click on the button 'Config Editor' Accept the warning. In the about:config dialog, search for: security.tls.version.min Double-click on the found preference security.tls.version.min and change its value to 1, and click on OK

Restart Thunderbird and try to download your messages.

Some people have also discovered they needed to change the following as well. In same location - Config Editor - change the following so value is 'True'. security.tls.version.enable-deprecated = true

more options

I tried your suggestion. While certainly much appreciated, unfortunately, it did not cure the problem. I still get the msg:

"Sending of the message failed. Peer’s certificate has an invalid signature. The configuration related to xxxxxxx.com must be corrected".

There's a blockage somewhere, and as my email hosting SP don't want to own the problem, all I can think of as a possible solution is to delete the current Thunderbird installation and to copy the working profile I saved as backup into a fresh copy of Thunderbird.

Thank you for your time and patience.

more options

Which security software (antivirus) are you running on Windows 10?

more options

To all the kind souls who came to my assistance. I solved the problem by deleting Thunderbird, by clicking the hamburger - selecting help - troubleshooting information - profile folder and by copying an earlier backup into the new Thunderbird profile. I lost some emails, not many, and now I'm up and running again. Thank you, people!