Yonke imikhiqizo Community Forum

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

When my message filter uses the "Reply with Template" action, the reply e-mail is always PGP encrypted, even when I do not have any public key for the recipient e-mail address. As a result, the reply e-mail is always corrupted.

I am using Thunderbird 140.7.1esr on Windows 10.

I have attached a screenshot of what the reply e-mail always looks like.

In the Template that I am using, the "encrypt" button is not selected, and in the OpenPGP menu of the Template, the "Encrypt" menu item does not have a checkmark next to it.

Does anyone know how I can get Thunderbird to send reply e-mails without using encryption?

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?

DEUTSCH (English see below(:

Hallo zudammen,

Konfiguration: - Window11 25H2 (aktuell) - Thunderbird Beta-6 (BuildID=20260213180051) - gpg2.5.17 (Gpg4Win 5.0.1); siehe auch: <https://www.gpg4win.de/>

Der bisherige und standarmärige Installationspfad von "Gpg4Win": "C:\Progam Diles (x86)\Gpg4Win\" wurde softwareseitig auf: "C:\Progam Diles\Gpg4Win\" geändert!

Bug 1967121 (Closed) => thunderbird148 --- fixed! <https://bugzilla.mozilla.org/show_bug.cgi?id=1967121>

Zur Zeit verfolge ich die Änderungen bezüglich der externen Schlüsselverwaltung in Thunderbird-Beta, da das Arbeiten mit externen Schlüsseln in der esr- und in der relesease-Version von Thunderbird seit der offiziellen Herausgabe von gpg2.5.x absolut nicht mehr möglich ist! Die geheimen Schlüssel für das Entschlüsseln und Signieren werden mit gpg2.5.x nicht mehr gefunden!

In der Schlüsselverwaltung von TB-Beta befinden sich meine öffentlichen Schlüssel und alle öffentlichen Schlüssel meiner Kommunikationspartner. Extern sind meine geheimen Schlüssel gelagert. Folgende Präferenz wurde aufgrund von gpg2.5.x hinzugefügt:

https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2026-02-26-10-04-58-df59be.png

Allerdings erscheint nach all diesen Maßnahmen die Fehlermeldung: "The secret key that's required to decrypt this message is not availlable."

https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2026-02-26-10-05-45-d8280e.png

Mit Herausgabe von Thunderbird/148.0 (release) sind dort die gleichen Probleme mit der externen Schlüsselverwaltung zu bepbachten!

Mit Versionen gpg < 2.5 funktioniert unter Windows alles problemlos!

UNTER LINUX haben hier Änderungen an der Präferenz: "mail.openpgp.load_untested_gpgme_version" nachweislich keinerlei Auswirkungen!

Was übersehe ich?

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

ENGLISH:

Hello,

Configuration: - Window11 25H2 (current status) - Thunderbird Beta-6 (BuildID=20260213180051) - gpg2.5.17 (Gpg4Win 5.0.1); see also: <https://www.gpg4win.de/>

The previous and default installation path of "Gpg4Win": "C:\Program Files (x86)\Gpg4Win\" has been changed by the software to: "C:\Program Files\Gpg4Win\"!

Bug 1967121 (Closed) => thunderbird148 --- fixed! <https://bugzilla.mozilla.org/show_bug.cgi?id=1967121>

At the moment, I’m following the changes regarding external key management in Thunderbird Beta, because working with external keys in the ESR and release versions of Thunderbird has become absolutely impossible since the official release of gpg 2.5.x! The secret keys required for decryption and signing are no longer found when using gpg 2.5.x!

In Thunderbird Beta’s key manager, my public keys and all public keys of my communication partners are present. My secret keys are stored externally. The following preference was added because of gpg 2.5.x:

https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2026-02-26-10-04-58-df59be.png

However, even after all these measures, the following error message appears: **"The secret key that's required to decrypt this message is not available."**

https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2026-02-26-10-05-45-d8280e.png

With the release of Thunderbird 148.0 (release), the same problems with external key management can be observed there as well!

With gpg versions **older than 2.5**, everything works flawlessly under Windows!

• • UNDER LINUX**, changes to the preference

"mail.openpgp.load_untested_gpgme_version" have demonstrably no effect at all!

What am I missing?

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!!

On Monday, 17 November 2025 the Security Certificate expired and I stopped receiving emails both on my computer and Andriod Device. As a result I am not receiving any emails through Thunderbird, but I can go to email host site to view them.

I logged in my computer tonight and clicked here and clicked there and the error message: "The certificate for mail.homebizmall.net is not valid for that server. Someone could be trying to impersonate the server. Create an exception but this could mean that someone has stolen your certificate and may be able to impersonate you."

So it seems the POP server and the SMTP server certificates were only valid for 3 months and I was FORCED to create the exception for both servers. Now I am worried the security has been breached.

By clicking here and clicking there, I stumbled on a few people who seem to have this problem, but each with their own limitations. My operating System is Windows 10 without the option to upgrade. I have not extended the security updates because I don't understand if it is just the operating system uploading to the cloud or everything on my computer and I am not prepared to do the latter.

Is it safe to leave the band aid on that I have used for the moment? Can I create an exception for the phone? Or is there a glitch that someone needs to walk me through fixing?

Thanking you in advance

Clinton

I keep getting a certificate error on my Thunderbird. The certificate refers to an email account i no longer have (Personal domain) and i have removed the account in thunderbird, and also removed previous certificate exceptions.

I have been through all menus and settings, and cannot find anywhere where it refers to that domain (and subdomain) I have also removed one entry with that FQDN in the outgoing server section.

What to do?

When someone sends me a msg, it displays along with the HTTP equivalent? Trying to figure out what setting is out of Wack such that I ses the HTTPS display of the message? Thanks

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 an error for an outdated certificate on my mail smtp server and when I try to add a security exception Thunderbird does absolutely nothing when i click the button to add a security exception where I can send mail. I end up having to cancel the window and discard my email. It will also not go view the certificate and if you ask it to check it just hangs up forever in and endless loop of checking.

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 downloads Firefox, Firefox Nightly, Firefox Developer.

All edition not write SSLKEYLOG to file.

I set the SSLKEYLOGFILE env.

How to enable ssl key log file?

Hello, I put the HTTPS mode Only mode on my OS for Imac, and I would like to put it on my iPhone 14, but I can't find how to do it, can you help me? THANKS. Best regards, christophe

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

I am using Firefox version 140.4.0esr (64bit) Only on Firefox: when trying to connect with Pirates' web page, I have a block which reads:

Security Connection Failed - no common encription algorithems      Error Code: ssl_error_no_cypher overlap

To The Official Site of The Pittsburgh Pirates/pirates.com:Homepage

I have tried to contact them with no luck.

Can you help?

Thanks,

David Martin ([edited email from public community support forum])

My mobile package site shows mixed-content warnings on Firefox — how can I fix this? Hello everyone, I run a website, which provides information about mobile phone prices and SIM packages in Bangladesh. Recently, I noticed that when users visit some pages in Firefox, the browser shows a “mixed-content” warning or blocks certain scripts. The same pages load fine in Chrome. All my URLs use HTTPS, and I’m using a LiteSpeed server with Cloudflare CDN. Could this issue be related to how Firefox handles external resources (like embedded operator banners or analytics scripts)? What’s the best way to debug and fix mixed-content problems in Firefox Developer Tools? Any detailed guidance or best practices would be greatly appreciated. Thanks in advance!

Hello,

I had issue to verify the cert on android app for https://partners-enrichment.heytelecom.be. On Windows I didn't have the same issue.

version 144.0.2 / build id 20251027123126 / target arm64-v8a armeabi-v7a x86_64 Device: Samsung S22 / One UI 7.0 / Android version 15 / version S901U1UES8FYI2 / Security patch level September 1, 2025

Error: Secure Connection Failed, because its certificate issuer is unknown, the certificate is self-signed, or the server is not sending the correct intermediate certificates.

CertChain RCA: DigiCert Global Root G2 DCA: DigiCert Global G2 TLS RSA SHA256 2020 CA1 cert: partners-enrichment.heytelecom.be

1) I couldn't check the cert from the gui as on windows. Shield in search bar / Connection not secure doesn't opened the cert. Is it expected?

2) I found this helppage: https://support.mozilla.org/en-US/kb/setting-certificate-authorities-firefox

Unfortunately about:preferences isn't available on android (ref. https://www.reddit.com/r/firefox/comments/u593x0/how_to_access_to_aboutpreferences_on_android/)

I see in about:certificate which is the correct RCA (I verified the pem file with the root). DigiCert Global Root G2

Where do I check the Intermediate CA's (DCA)?

3) When exporting the RCA it has been download as: digicert-global-root-g2.pem.txt Why the txt at the end?

On Windows it downloads as digicert-global-root-g2.pem

Kind regards,