Форум спільноти Thunderbird

From Microsoft: "Recent Outlook Mobile updates introduced a stricter and more standards-aligned S/MIME message structure. The messages themselves are valid, but some third‑party mail clients such as Thunderbird do not fully support the way Outlook mobile structures the encryption. As a result, these clients may display a blank message body even though the encrypted content is present.

As a workaround, if you need to send encrypted mail to recipients who use third‑party clients, use Outlook desktop or Outlook on the web instead of Outlook mobile. These versions generate encrypted messages in a format that is more widely supported. "

I couldn't find this reported anywhere in these forums. Is there a solution being worked on to address this issue? Or has anyone found a workaround? We are stuck with using the Outlook app until the Thunderbird app supports S/MIME.

Hello.

I have added a new account to Thunderbird, and it is not syncing to show new messages. I am getting a pop-up from Tbird saying "The certificate for mail.newcreationloughborough.uk is not valid for that server ..." etc. I have gone through the procedure titled 'Troubleshooting email client warnings about invalid server certificates' to add Norton's certificate to my email app (as directed by the 'resolve' link in the 'Resolve email sync issues caused by certificate warnings' from the Norton EE Cyber Security add-on), and it tells me that the certificate is already installed.

What can I do next to get it to sync?

When I export my private key and add more user IDs to it, GPG adds extra feature flags that apparently aren't supported in Thunderbird. I've tried following the directions here, but GPG doesn't seem to do anything different with the --rfc4880 flag, and so importing the key back into Thunderbird still gets the "unsupported features" warning.

Even when creating a key in Sequoia-PGP, it seems to add an extra notation? And that also seems to make Thunderbird say it's an extra unsupported feature.

Am I doing something wrong?

I am getting this message when I try to send email. All of my settings are correct. 'Sending of the message failed. Unable to communicate securely with peer: requested domain name does not match the server’s certificate.

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.

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"

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!

Bonjour, Hello I add new exception (see image, for every count on the servers hosted on retzien.fr, and I have to valid and valid and valid... for every access. See image. TB 140.(64 bits) Ubuntu 24.04.3 LTS AMD Ryzen 2700X x 16 16 Go Cheers

I have just installed Thunderbird, am continually getting "certificate for outlook.office365.com" not trusted. I have added Thunderbird to my Malwarebytes exception list, but the the notice continue to come. I have ensured that OAuth2 is the correct authentication method, but the messages persist.

Is there something else I can do to stop these messages?

Would be very grateful, thank you.

Tim Harrison

Good morning

Thunderbird is not sending or receiving emails, i already deleted the gmail account and reinstalled it but it didn't work upon installation i get the attached message.

this was running on a windows 7 pc with no issues for about 2 years.

thanks in advance

Hi All. New to Thunderbird but liking what I see. Am trying to install a new certificate but keep seeing the same error message when I attempt to send an email:

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.

So here is what we know:

The certificate seems to work (I've sent test emails to a couple of test email accounts) when I use it in Outlook safe mode. Can't get it to work in normal Outlook mode because of add-ins, hence my switch to Thunderbird. They seem to appear fine in the S/MIME section for digital signing and encryption and I can even see the certificate when I go into Manage S/MIME Certificates.

Has anyone come across this before / got any ideas about how to resolve this? Thanks!!

Over a month ago I began experiencing an error message when attempting to send emails from my gmail account using Thunderbird (TB). Error msg reads: Sending of the message failed. An error occurred while sending mail. The mail server responded: Must issue a STARTLS command first. For more information go to: https://support.google.com/a/answer/3221692 and review RFC 3207 specifications. 00721157ae682-765bb916a90sm38332507b3.4-gsmtp. Please verify that your email address is correct in your account settings and try again.***While I have looked at all of this, I can't really find a solution I know how to implement.***

I can send emails using Google webmail and when I do, the emails show up in my TB Sent items folder. I'm totally stumped and considering moving to Outlook. But TB has been perfect for me for years and I want to stay with it. Any help will be much appreciated!

We are testing EDI messaging with a government department however it seems that Thunderbird keeps stripping the attachment before the email reaches the exchange and produces this error.

We sent 3 messages:

1. 2 had this error: PKCS#7 argument error: malformed S/MIME encoded PKCS#7 object 2. 1 had this error: no attachment on their end

PKI Certificate is installed in Thunderbird.

I have suddenly started to receive this message when I open Thunderbird "Certificate for IMAP Gmail does not come from a trusted source". When I click on this message I get the attached screenshot.

I've gone through the forums by I can't understand what it is written. It seems like everything that is written is designed for people who have a good understanding of technology. I don't but I was able to determine that the OAuth is properly set.

I am using 128.14.0esr (64-bit) Thunderbird for Linux Mint mint-001 - 1.0 Updates disabled by system administrator Currently on the esr update channel

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>

Hi! I have a valid SMIME certificate and a valid private and public GPG key imported into Thunderbird. When I try to write an email to myself and signing and encrypting it it switches to SMIME every time I click „encrypt“. I can only select GPG, if I only sign my message and do not encrypt it.

Here is a video of this behaviour (link points to video on cryptpad.fr) Here is a video of this behaviour

Any hints? Is there a mechanism which technology is prefered?

Thanks! Thomas

My thunderbird account stopped receiving emails yesterday and is giving the message:

"Thunderbird The certificate for pop3.exemail.com.au is not valid for that server. Someone could be trying to impersonate the server and you should not continue."

Mails are still going to the Webmail account and my husband has an exemail account with the same settings that is working correctly.

Exetel is in the process of selling its email service to a third party but this isn't final until September 8, will moving to the new provider fix this issue or is there something else I should be doing?

hello; I am trying to install a new email account on Thunderbird. System found configurations by it self and showed up a Add a Security Exception box. Whatever I do, nothing works. I checked and unchecked the "Permanently store this exception" box, clicked "Confirm the Security Exception", nothing works, I am stuck there. I tried to setup manually according to Webador (my email and server host) details info, it does not work either. I have been researching for weeks now... as we have multiple email addresses to deal with, Thunderbird is really valuable. Anyone can help us? Merci,