The expired certificate was generated by AVG. You need to disable SSL/TLS scanning in AVG, or get rid of AVG altogether because you really don't need any other antivirus except Windows Defender which is built into Windows 10. Alternatively, you should update or uninstall and install the latest AVG release to get a newer/valid certificate.

After you updated to 68, Thunderbird created a new default profile that's why you couls not access your emails and addresses. The old profile is not truly gone, just forgotten or ignored, but you can tell Thunderbird to continue using that old profile. Go to Help > Troubleshooting Information > about:profiles > Launch in new browser under the profile that is NOT in use and default. This will be the old/lost profile with your stuff, so once Tbird opens with it, close the other Tbird window then set the old profile as the default from the same About Profiles tab.

Thank You Stans for Your quick reply.

I have uninstalled AVG and restarted my PC but I got the same result as before when I tried to send a mail  ????

best regards / Lasse

Today I got the same result when I tried to retrieve my mail by Thunderbird. So now I can't neither send nor retrieve mail to my PC with Thundrbird best regards Lasse

The invalid AVG certificate is definitely still in your system. You should remove it from Thunderbird's certificate store. Unfortunately, the uninstallers of most antivirus/security software do a poor job of removing the software from your system, so a lot of leftover files and folders remain even though the software is not running anymore. These leftovers can prevent Windows Defender from going active until they are removed. Open Windows Security Centre and see if Defender is active and running and also remove the AVG certificate from Tbird's certificate store. I've sent you a link to the AVG site that covers importing of the certificate into Tbird. It shows you where to look in Thunderbird, and what to do with the invalid certificate error IF you choose to reinstall AVG on your system.

Help/Troubleshooting, click Open Folder, close TB, delete or rename key4.db, cert9.db and logins.json. This will reset all certificates and account passwords. The files will be automatically recreated when TB restarts, and you are prompted to enter the account passwords.

If you stay with Windows Defender, add the TB profile folder as an Exclusion in WD settings.

I have tried to follow your instructions. Yes as what I can see the Defender is running But I don't know how to remove the AVG certification from Thbirds certification store. You write that You have sent a link to AVG site ... but I can't find the link?? I am not going to reinstall AVG

Next mail starting "Help/Troubleshooting I have used Help/troubleshooting but then Open Foder????? Kant find that What's comes up is:

Troubleshooting information This side contains technical information which can be to help when you try to solve a problem. If you want to see the answer for the most common questions about Thbird you can visit

our supportwebbsite.

and then a long list in blue: Program facts

I have the swedish version of Thbird and have tried to translate it to Englich Sorry!! Best regards Lasse

I've attached a picture of the Troubleshooting tab and Open Folder marked with red. Maybe you see something like öppen mapp - profilmapp. Close TB before editing any files.

Hello again and thank you for all your help I have now renamed the three files you asked me to do. (TB not running) and then restarted TB and tried to send a mail but with the same result as before. However I have not added the TB profile folder as an Exclusion WD setting. How shall I do this? Best regard Lasse

To add an Exclusion to WD:

https://support.microsoft.com/en-ca/help/4028485/windows-10-add-an-exclusion-to-windows-security

I suspect this won't fix the certificate error. Does it still refer to an AVG cert.?

It looks like I get the same response when I try send a mail. Were could You see the reference to AVG certificate?

I have used connection security: "SSL/TLS" and "password "

However if I send a mail with connection security "Non" and no password I got a message saying

"It was not possible to send the message The message could not be sent because the connection to the outgoing server smtp.glocalnet.net did time out.

Did it help you? best regars Lasse

Hello again, If we go back to the cryptical message: "Lägg till säkerhetsunderlag" (Security basis) what does it mean the message asks for "hämta certificate" (get certificate) I have not done that because it also says:

  Legitimate banks, shops and other public websites don't want you to do this.

What does this mean? I could not understand the meaning of the message and what to do?

best regards Lasse

Were could You see the reference to AVG certificate?

The screenshot you attached.

I have used connection security: "SSL/TLS" and "password " However if I send a mail with connection security "Non" and no password I got a message saying "It was not possible to send the message The message could not be sent because the connection to the outgoing server smtp.glocalnet.net did time out.

You should only use the settings supported by your email service provider. If the provider says you use SSL/TLS and a normal password, then that's exactly what you should use. Changing these to any other values will only add to the problem, so revert them to their original working values, unless your provider has changed what they now use. Get the right settings from the provider if you're unsure what they should be.

You write that You have sent a link to AVG site ... but I can't find the link?? I am not going to reinstall AVG

I did, via the private messaging function of this forum because not all links are allowed in this section. One link points to the AVG Remover utility, while the other point to a tutorial about invalid AVG SSL/TLS certificate, which is what was shown in your screenshot. Run that AVG Remover as per the instructions, to get rid of remnants of AVG and hopefully it will also remove that invalid certificate from the system.

Do you still get the same invalid certificate error even after deleting/renaming the cert9.db file? If you do, go to Options > Advanced > Certificates > Manage Certificates. This will open Tbird's internal Certificate Manager. Switch through the tabs and look for AVG's certificates, especially under the Servers tab. Delete/Distrust any AVG certificate that you find. Don't touch any other certificate. Also look under the Authorities tab. Take your time, there are many certificates there, so be careful to not remove any other certificate except AVG ones, then restart Thunderbird.

It looks like I get the same response when I try send a mail. Were could You see the reference to AVG certificate? I have used connection security: "SSL/TLS" and "password " However if I send a mail with connection security "Non" and no password I got a message saying "It was not possible to send the message The message could not be sent because the connection to the outgoing server smtp.glocalnet.net did time out. Did it help you? best regars Lasse

The AVG certificate was noticed in the picture of your original post. Since removing AVG, is the reference still in the error, or is another issuer mentioned?

I can't find a recent description of the server settings for smtp.glocal.net. Try setting the port to 25, connection security = none, authentication = no authentication or password, transmitted insecurely, User Name = email address.

Hello again. - I was wrong - there is another invalid certification: GlobalSign Organisation Validation CA

look at the connected picture

best regards

I can't offer any advice about GlobalSign, but I urge you to contact glocal to find out exactly what are the correct server settings. Until we know that, it's pointless to make any recommendations.

Ok you said that I should contact "glocal" do you mean glocalnet.net my e-mail coordinator or do you mean GlobalSign?

responsible for glocalnet.net is Telenor Sverige AB and when I logon at Telenor I got the following rekomendation how to define my mail client:

Name and username. ansa.lasse@glocalnet.net E postadress: ansa.lasse@glocalnet.net password: same as to logon to webmailkonto Incomming server: pop.glocalnet.net outgoing server: smtp.logalnet.net SMTP-port: 587 Portnumber for secure mail POP: 995 IMAP: 993 SMTP: 465

I have tried (I think) all combination both with sertified connecton with password and without serification and password but it does not work

However if I send a mail when I have the definitions: "No autentification" and "no password"

I got first a message saying " Connection to smtp.glocalnet.net" and after a while I got the message:

"It did not manage to send a message." - The message could not be sent because the connection to outgoing server smtp.glocalnet.net did time out. Try again.

What is the correct server name, smtp.glocalnet.net or smtp.logalnet.net? The second one doesn't seem to exist. According to the info given by Telenor, it would be smtp.glocalnet.net on port 465, SSL/TLS, authentication = normal password, User Name = email address or just part before the @ (not sure). Telenor also has an smtp server smtp.bredband.net with the same settings.

I'm sorry this a confusing mess, but it's mainly due to the lack of documented instructions from your mail provider.

Not only lack of documented instructions from Telenor, but also an expired certificate issued for the *.glocalnet.net domain. The certificate was issued by GlobalSign, and has since expired. Thunderbird is warning you that the certificate used by the *glocalnet.net mail server is invalid (expired). This needs to be addressed by Telenor, they need to renew that certificate. You can tell Thunderbird to trust the expired certificate by adding a permanent exception for it, and it will stop bringing up that certificate verification prompt.