Thunderbird: форум сообщества

Why do I suddenly (from one day to another) receive the message: "Das Zertifikat für imap.gmail.com stammt nicht von einer vertrauenswürdigen Quelle."

when trying to downlowd messages from Gmail?

I have not changed anything at all.

My e-mail provider has done the annual update of security and provided a new e-mail cert; however, Thunderbird no longer successfully updates it.

Thunderbid gets to the point of confirming the security exception; however, does not proceed.

This is using ThunderBird 140.4.0esr (64-bit) from Ubuntu Snap, on Ubuntu LTS 24.04.3.

Certificate errors have been an ongoing, several-times-a-day frustration for me and other users, with different ISPs, since approximately June 25. Is anyone working on this bug? Because it clearly is a bug: Not only I but several other users have reported that Thunderbird worked fine until that date, then stopped working fine. What changed, and can it be put back the way it was, or can we receive some explicit instructions on how to fix it for ourselves? It's making Thunderbird borderline unusable. Every time I try to send a message, I have to confirm a security exception, then send it again. Several times a day, when I try to fetch messages, I have to confirm security exceptions. The confirmations never seem to stick. This is some BS.

I am able to receive emails on Thunderbird but I am not able to send emails to anybody from Thunderbird. That happens on two computers I have. I am able to send emails from Outlook. Therefore, it is not my email provider's (BluePeak) problem. When I try to send an email from Thunderbird, I receive the following error message: “Sending the message failed. SSL received a record with an incorrect Message Authorization Code. The configuration related to must be corrected.”

Please help me resolve this issue. Thank you very much!

I have 4 emails in Thunderbird, one of those I also have on my phone, it is receiving mail, on my desktop, two of the emails have no email today, and two I have only one email, all should have 10 to 20 or more emails. I do have the emails on the website, but they are not loading onto Thunderbird. I get this message, "The certificate for imap.knology.net is not valid for the server. Someone could be trying to impersonate the server and you should not continue.

 Can you offer any help?

Server Posteingang IMAP (empfohlen) imap.vodafonemail.de Ports für Posteingang IMAP SSL: 993 / TLS: 143

Server Postausgang SMTP smtp.vodafonemail.de Ports für Postausgang SSL: 465 / TLS: 25 oder 587

Bonjour

Depuis quelques jours je rencontre le message suivant:

L’envoi du message a échoué. Une erreur est survenue lors de l’envoi de l’e-mail. Le serveur e-mail a répondu : 1jHjuyBzCXgNw StartTLS obligatoire. StartTLS mandatory.OFR303_199 [199]. Veuillez vérifier que votre adresse e-mail dans les paramètres du compte est correcte et essayer à nouveau.

Dans les paramètres du compte tout semble OK Merci pour votre aide Cordialement

Hi

I have a problem with Thunderbird which might be a bit niche but here goes...

The first attempt at sending an email fails as TLS Record Layer v1 is used, the mail server sees this and hard resets the connection so sending halts. See attached Wireshark trace screenshot "Failed".

If I retry the send again Thunderbird uses TLS Record Layer v1.3 and the email goes out ok. See attached Wireshark trace screenshot "Success".

If I send another message immediately no problem but if I wait 20-30 minutes the above cycle happens again.

I have set the minimum TLS version in the config to 1.3 (option 4) and restarted Thunderbird but this has not changed anything.

Any ideas how I can fix this? It's a pain because automated replies don't work.

I can't send mail via smtp.comcast.net. I can connect to IMAP and get mail, and I can send from my iphone and (new) Outlook. Running TB v142.0 (64 bit) on Windows 11. Issue is reproducible on second system. When I try to send mail, client tries for 1 minute, then times out with "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.comcast.net timed out. Try again."

TB log says: 14:17:11.775 1756750631775 addons.xpi WARN Checking C:\Program Files\Mozilla Thunderbird\distribution\extensions for addons 14:19:37.714 mailnews.smtp: New client instance SmtpClient.sys.mjs:121:17 14:19:37.716 mailnews.smtp: Connecting to smtp://smtp.comcast.net:587 SmtpClient.sys.mjs:141:19 14:19:37.799 mailnews.smtp: Connected SmtpClient.sys.mjs:429:17 14:20:39.211 mailnews.smtp: NetworkError: a Network error occurred SmtpClient.sys.mjs:476:17

   _onError resource:///modules/SmtpClient.sys.mjs:476

14:20:39.212 mailnews.smtp: Socket closed. SmtpClient.sys.mjs:550:17 14:20:39.214 mailnews.smtp: SecurityError info: PR_END_OF_FILE_ERROR SmtpClient.sys.mjs:491:21 14:20:39.245 mailnews.send: Sending failed; The message could not be sent because the connection to Outgoing server (SMTP) smtp.comcast.net timed out. Try again., exitCode=2152398868, originalMsgURI=imap-message://mgiul%40comcast.net@imap.comcast.net/Drafts#57692 MessageSend.sys.mjs:343:32

smtp.comcast.net is using a self-signed cert. Is this the problem? C:\Users\rchar>openssl s_client -starttls smtp -connect smtp.comcast.net:587 Connecting to 96.103.145.180 CONNECTED(000001F8) depth=3 C=GB, ST=Greater Manchester, L=Salford, O=Comodo CA Limited, CN=AAA Certificate Services verify error:num=19:self-signed certificate in certificate chain verify return:1 depth=3 C=GB, ST=Greater Manchester, L=Salford, O=Comodo CA Limited, CN=AAA Certificate Services verify return:1 depth=2 C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Certification Authority verify return:1 depth=1 C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Organization Validation Secure Server CA verify return:1 depth=0 C=US, ST=Pennsylvania, O=Comcast Corporation, CN=smtp.comcast.net verify return:1 --- Certificate chain

0 s:C=US, ST=Pennsylvania, O=Comcast Corporation, CN=smtp.comcast.net
  i:C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Organization Validation Secure Server CA
  a:PKEY: RSA, 2048 (bit); sigalg: sha256WithRSAEncryption
  v:NotBefore: Jan  6 00:00:00 2025 GMT; NotAfter: Jan  6 23:59:59 2026 GMT
1 s:C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Organization Validation Secure Server CA
  i:C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Certification Authority
  a:PKEY: RSA, 2048 (bit); sigalg: sha384WithRSAEncryption
  v:NotBefore: Feb 12 00:00:00 2014 GMT; NotAfter: Feb 11 23:59:59 2029 GMT
2 s:C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Certification Authority
  i:C=GB, ST=Greater Manchester, L=Salford, O=Comodo CA Limited, CN=AAA Certificate Services
  a:PKEY: RSA, 4096 (bit); sigalg: sha384WithRSAEncryption
  v:NotBefore: Jan  1 00:00:00 2004 GMT; NotAfter: Dec 31 23:59:59 2028 GMT
3 s:C=GB, ST=Greater Manchester, L=Salford, O=Comodo CA Limited, CN=AAA Certificate Services
  i:C=GB, ST=Greater Manchester, L=Salford, O=Comodo CA Limited, CN=AAA Certificate Services
  a:PKEY: RSA, 2048 (bit); sigalg: sha1WithRSAEncryption
  v:NotBefore: Jan  1 00:00:00 2004 GMT; NotAfter: Dec 31 23:59:59 2028 GMT

--- Server certificate

MIIHATCCBemgAwIBAgIRAJUASDPOQisnR1zo9CfhXcYwDQYJKoZIhvcNAQELBQAw gZYxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAO BgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBDQSBMaW1pdGVkMTwwOgYD VQQDEzNDT01PRE8gUlNBIE9yZ2FuaXphdGlvbiBWYWxpZGF0aW9uIFNlY3VyZSBT ZXJ2ZXIgQ0EwHhcNMjUwMTA2MDAwMDAwWhcNMjYwMTA2MjM1OTU5WjBdMQswCQYD VQQGEwJVUzEVMBMGA1UECBMMUGVubnN5bHZhbmlhMRwwGgYDVQQKExNDb21jYXN0 IENvcnBvcmF0aW9uMRkwFwYDVQQDExBzbXRwLmNvbWNhc3QubmV0MIIBIjANBgkq hkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoLkgKQUqw4MylCObwwzTyFkIoMN/NRNl 6EY0zS+sjlYMFPplSULdfqs1tEcWZhCs+u1EkJN9+/juCtzeZ9c73yx8nTph0/KZ 5ri9t55yu5xhtuDv2WsMJmqcTOHPXRSZt7abpsvNfxCb6IG2YdPrBNqPyZPEJ6jn h3CY3qBbsreL4iR+UEGunSJAg2mRXHhx0/aYN3CTUetOcSBzIwoFXPklptWCcm5V knK+BWqFtKlyt6nHW/o2qK74nLDgKNUgxR9pG/Bw48ZER1emGsNlN2RVyOBtoAAG 15x4vD2iFBVEe9A0q9HOJc9bGSNb6zuU4ZpCb+RpNq3kkqJCpS6aJwIDAQABo4ID gDCCA3wwHwYDVR0jBBgwFoAUmvMr2s+tT7YvuypISCoStxtCwSQwHQYDVR0OBBYE FHz0nGUjqJ0rg0OQFz/hLkJ581OVMA4GA1UdDwEB/wQEAwIFoDAMBgNVHRMBAf8E AjAAMB0GA1UdJQQWMBQGCCsGAQUFBwMBBggrBgEFBQcDAjBKBgNVHSAEQzBBMDUG DCsGAQQBsjEBAgEDBDAlMCMGCCsGAQUFBwIBFhdodHRwczovL3NlY3RpZ28uY29t L0NQUzAIBgZngQwBAgIwWgYDVR0fBFMwUTBPoE2gS4ZJaHR0cDovL2NybC5jb21v ZG9jYS5jb20vQ09NT0RPUlNBT3JnYW5pemF0aW9uVmFsaWRhdGlvblNlY3VyZVNl cnZlckNBLmNybDCBiwYIKwYBBQUHAQEEfzB9MFUGCCsGAQUFBzAChklodHRwOi8v Y3J0LmNvbW9kb2NhLmNvbS9DT01PRE9SU0FPcmdhbml6YXRpb25WYWxpZGF0aW9u U2VjdXJlU2VydmVyQ0EuY3J0MCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5jb21v ZG9jYS5jb20wggGABgorBgEEAdZ5AgQCBIIBcASCAWwBagB2AJaXZL9VWJet90OH aDcIQnfp8DrV9qTzNm5GpD8PyqnGAAABlDwZ58gAAAQDAEcwRQIhAOgI6NbRS4t6 9XvPVbmFixPHyFJXDqU60dv5r+RB9Y9YAiAwlfQhXe45ccND3T5te2KryuxvRhzW aBO3oIS6ixw6DAB3ABmG1Mcoqm/+ugNveCpNAZGqzi1yMQ+uzl1wQS0lTMfUAAAB lDwZ56oAAAQDAEgwRgIhAKmynGx19jBgk4Xy/eChCKjR/vpOtCH16470/jJyY6Yy AiEAkwlRN7Cn1AN20CGjNowsJ2PBaqNOk/u297W/RttgBKMAdwDLOPcViXyEoURf W8Hd+8lu8ppZzUcKaQWFsMsUwxRY5wAAAZQ8GefaAAAEAwBIMEYCIQDyR2Zz3Spd 0Gul6Z2dJa15aUEiEaW7KEAtbCcqz/zoLwIhAIV8YxWeI8rVaAvdl9kWquejUOTx M2G4iYjeZINb1VMgMEMGA1UdEQQ8MDqCEHNtdHAuY29tY2FzdC5uZXSCEHNtdHAu eGZpbml0eS5jb22CFHd3dy5zbXRwLmNvbWNhc3QubmV0MA0GCSqGSIb3DQEBCwUA A4IBAQBgn3Z51e8DZ/bO/AFqc22A4e5EqfUx4y6itcaz3mnQcU9pAsA/LK/WeY+e PtHIkWNKFlysJSbU2ByJ/6+bnebalXgRZ3sAeB2Z7UIUIHEjhcEQE2s4CxAXBiI7 SgqWjrw/Qj+AOghhMwayhIjmnNk34MmyY4f9KsAC6fIEn9ypCxuaN4lrwZcmS8iK o6PRho6pd837BEaRNIZBQpI/8WKxoKsNOu8bw8FwX/Zn8q+1oPo+0sQkmSmWOruu l8tlq8boA5R6YSBWek8hxmEZppvBs55wfNCnr2DQ4CgAREJZMKt6PIiKlgQ9r58b OSb5otnW7xsrx3SKM2zlvRA5mhfL

subject=C=US, ST=Pennsylvania, O=Comcast Corporation, CN=smtp.comcast.net issuer=C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Organization Validation Secure Server CA --- No client certificate CA names sent Peer signing digest: SHA256 Peer signature type: rsa_pss_rsae_sha256 Peer Temp Key: X25519, 253 bits --- SSL handshake has read 6708 bytes and written 1662 bytes Verification error: self-signed certificate in certificate chain --- New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384 Protocol: TLSv1.3 Server public key is 2048 bit This TLS version forbids renegotiation. Compression: NONE Expansion: NONE No ALPN negotiated Early data was not sent Verify return code: 19 (self-signed certificate in certificate chain) --- 250 OK --- Post-Handshake New Session Ticket arrived: SSL-Session:

   Protocol  : TLSv1.3
   Cipher    : TLS_AES_256_GCM_SHA384
   Session-ID: 27FBCE0D025BF752A9F038657257E923F1E5560B92BB78A47C5C9E0FFFDBEF7B
   Session-ID-ctx:
   Resumption PSK: FAFF92690FBEDF157D2856329FDABB033F2A0948C5A0F668E4B69C197EC6E52B8DE8A676EA4A78EAEEED7E90C4935DEC
   PSK identity: None
   PSK identity hint: None
   SRP username: None
   TLS session ticket lifetime hint: 300 (seconds)
   TLS session ticket:
   0000 - 97 cc 16 34 49 69 e3 c2-8f 6b ab cb e0 53 cb c1   ...4Ii...k...S..
   0010 - e0 31 10 bf c8 94 c5 d1-59 2b 3e 84 f7 63 44 be   .1......Y+>..cD.
   0020 - 3e d6 69 b0 d4 10 7a 1a-4f 6a da 21 91 6b 34 f2   >.i...z.Oj.!.k4.
   0030 - 1c 2c df cc 5f ee b5 ce-4c 71 49 b0 28 d6 7b 92   .,.._...LqI.(.{.
   0040 - 9e 6a dd bb 93 ca 9e 44-80 1f df ec f7 e4 95 04   .j.....D........
   0050 - 7c c1 6b 1d 86 59 7c 18-7d 98 41 0d 04 a1 f1 ae   |.k..Y|.}.A.....
   0060 - 7b 6d 68 ad 68 a6 b2 32-95 71 d3 89 09 ea 28 7c   {mh.h..2.q....(|
   0070 - ee 8f 67 1e ab e6 09 d7-5d c6 67 0d 0e 63 7b 24   ..g.....].g..c{$
   0080 - 87 cc fb eb 8f a8 c6 67-60 d2 70 e6 58 93 06 d0   .......g`.p.X...
   0090 - 1f ef 95 15 53 92 95 19-85 76 91 26 7c a1 9e 96   ....S....v.&|...
   00a0 - 12 9d bd b2 a9 38 45 05-a5 28 14 65 4c ac c0 6d   .....8E..(.eL..m
   00b0 - c6 65 e7 b8 4b ff 0c dd-58 82 c9 c5 de 8d 64 ab   .e..K...X.....d.
   00c0 - f4 59 c5 5c bc bd c2 e9-34 2a d7 a7 99 21 97 60   .Y.\....4*...!.`

   Start Time: 1756752732
   Timeout   : 7200 (sec)
   Verify return code: 19 (self-signed certificate in certificate chain)
   Extended master secret: no
   Max Early Data: 0

--- read R BLOCK --- Post-Handshake New Session Ticket arrived: SSL-Session:

   Protocol  : TLSv1.3
   Cipher    : TLS_AES_256_GCM_SHA384
   Session-ID: 13DA31F60D1C9A3207FFEA54D2CEC29BB0D44016068E3E79A18492F695B02E80
   Session-ID-ctx:
   Resumption PSK: 44D18B4AEB19CDEBA968E3BD867C3B0167C07C61DC3091072882660FC234D4B3B071B663546C5B4AC3E53A6A5C206A9B
   PSK identity: None
   PSK identity hint: None
   SRP username: None
   TLS session ticket lifetime hint: 300 (seconds)
   TLS session ticket:
   0000 - 97 cc 16 34 49 69 e3 c2-8f 6b ab cb e0 53 cb c1   ...4Ii...k...S..
   0010 - 09 52 42 f9 c9 f7 bc 99-5a b5 73 e3 9b b8 1c 91   .RB.....Z.s.....
   0020 - 16 f5 ea 33 20 29 e1 59-79 65 46 0a 4b ad b7 fe   ...3 ).YyeF.K...
   0030 - b4 aa b7 7b f8 57 36 10-71 09 19 c6 d2 64 c4 8a   ...{.W6.q....d..
   0040 - 47 f6 28 4b 62 9e be ca-d9 16 1a e7 df 7d 51 f7   G.(Kb........}Q.
   0050 - f6 66 04 fe 37 cf 0c bb-4f d8 d3 1b d6 06 be d0   .f..7...O.......
   0060 - 21 ee 9e 65 ac a3 18 80-31 b7 17 5b 23 d2 9d 4e   !..e....1..[#..N
   0070 - 57 f7 b0 66 01 5f cc c5-a1 a5 96 ee d2 d8 55 ed   W..f._........U.
   0080 - 5b 91 86 da 91 d5 3d 17-36 bd a5 97 58 ab fb ad   [.....=.6...X...
   0090 - eb eb 38 5e fd e3 7a 13-b9 f8 5c 14 f5 80 3a 72   ..8^..z...\...:r
   00a0 - 52 66 d9 23 8c a3 50 5c-3c e5 fc cb 22 21 11 3f   Rf.#..P\<..."!.?
   00b0 - a6 71 87 67 8b 33 8e b0-0a 65 46 f6 df 7a f0 f3   .q.g.3...eF..z..
   00c0 - 04 4e cf 22 ad 4d 45 69-53 9c 45 56 df 07 ae e3   .N.".MEiS.EV....

   Start Time: 1756752732
   Timeout   : 7200 (sec)
   Verify return code: 19 (self-signed certificate in certificate chain)
   Extended master secret: no
   Max Early Data: 0

--- read R BLOCK closed

C:\Users\rchar>

I am using a E-mail server that uses LetsEncrypt certificates. I was using Thunderbird 128 ESR without problems. When the certificate was updated, I was requested to confirm - then sending E-mails was possible. Now I have updated to Thunderbird 140 ESR. The E-Mail servers LetsEncrypt certificate was now updated but in Thunderbird I do not get any information about this, nor get I requested to check the new certificate. The SMTP connection just fails. The IMAP access to the E-mail server works fine. (IMAP and SMTP work both fine with K9-Mail on my mobile device)

How can I get Thunderbird to ask me again to check the updated certificate?

Am receiving a message reading-

The certificate for imap.gmail.com does not come from a trusted source.

After I did the 128.5.2esr update, none of my email accounts can get email with SSL/TLS on. It won't even try the server with SSL/TLS on. If I turn it off, then it can get mail. When I try to change to STARTTLS it will just hang showing checking server capabilities. Some accounts are imap and some POP3

Running Windows 10, version 22H2 updated 12/10/2024 OS Builds 19044.5247 and 19045.5247

Gmail works fine. I've tried the just about all of the things I have found online, but no luck.

Any suggestions? In the past I rolled back to a working version and that fixed it, but it hasn't worked this time. Would removing all of the certificates fix it? Didn't want to take that chance until I threw it out out here!

Thank you!

Running Thunderbird 140.8.0esr 64bit Windows 11 Home, v25H2 932GB storage 32GB ram i7-13700k

Recently, I've started getting the following message every time I launch Thunderbird: "The certificate for imap.googlemail.com does not come from a trusted source."

Digging into details I get: "you are about to override how Thunderbird identifies this site" "Location: imap.googlemail.com:993" "This site attempts to identify itself with invalid information" "Unknown Identity. The certificate is not trusted because it hasn't been verified as issued by a trusted authority using a secure signature."

Digging deeper into the certificate I find the issuer is Bitdefender who I use for antivirus and VPN. However, the VPN shows no effect when enabled or disabled. The validity period is 2 Feb 2026 to 27 Apr 2026

l can get email, but cant send it. Is Bitdefender at fault?

I'm stumped. What should I do???

Hello,

I am moving over to Thunderbird from outlook. I have about 8 emails with two domains. First email works okay. The second one on the same domain has turned red on the left panel and thunderbird keeps poppoing up the certificate for mail.xxx.com is not valid for the server. The other works I added the exception when setting it up. The mail server is another domain used from my cpanel hosting provider. So it does not match the domain of the emails.

I can't seem to find a way around this to get it to work. Also I under account settings it looks correct. I am thinking this error message is the incoming mail server? I don't see under account setting anything for incoming mail server which on my hosting is the same for incoming and outgoing. Appreciate any help.

Thank you!

I have several iterations of installing SMIME on my email account. I know the pf12 file is valid and it works on all my Android systems. However, when I try to send a digitally signed email on Thunderbird under Ubuntu, I get the message that either the SMIME certificate cannot be found or it has expired even though I went through the correct process to install it (and it shows up on the End to End Encryption settings) and when I display it, it indicates an expiry date of 2027. I have also tried to bundle it with the intermediate certificate but I still get the same error. I even tried to create my own personal SMIME certificate and use it (using SSL) and it had the same issue. Anyone have any suggestions?

This is the error I get: "Sending of the message failed. You specified that this message should be digitally signed, but the application either failed to find the signing certificate specified in your Mail & Newsgroup Account Settings, or the certificate has expired."

Do I need to put the SMIME certificate in a specific folder in order for it to be "re-found"

Typically if I experience a security certificate exception, thunderbird will popup the certificate exception box, I click to get certificate and am done.

Today I cannot get the certificate popup to appear. which is fine I know where the certificates are managed but I have not a clue how to add a certificate OR what information to enter into the "Add security exception" dialogue box

Any help would be greatly appreciated.

Здравствуйте, мы пользуемся программой Kaspersky Security Center, у нас возникла проблема. После изменения политики, постоянно меняется самоподписные сертификаты почты (Thunderbird) и каждый раз приходится подтверждать их заново. Просьба оказать помощь в решение данной проблемы.

________________________________________________________________ Hello, we are using the Kaspersky Security Center program, and we have a problem. After changing the policy, the self-signed mail certificates (Thunderbird) are constantly changing, and we have to re-verify them every time. Please help us resolve this issue.

Receive popup message: The certificate for mobile.charter.net does not come from a trusted source. In trying to send email, popup message: Sending the email failed. Peer's Certificate issuer is not recognized. The configuration related to mobile.charter.net must be corrected. Then it wants me to Add Security, Get Certificate.

Thunderbird 140.7.0esr allows me to e-mail my OpenPGP public key to myself, but it doesn't seem to have any way for me to get access to my private key. I was wondering how to export keys? Thanks!