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I've been a Thunderbird user for years without problem. However, since May 22, three specific messages continually reappear after deleting them from my Inbox.

I keep my Inbox empty and it stays that way, except for these 3 messages. Removing them from the Trash folder has not solved the problem.

My email provider is netaddress.com via POP3 account. I signed on to look at my inbox on their site via a browser, and the messages aren't there.

I have tried repairing and compacting the inbox, but the messages continue t reappear.

Do you have any other suggestions?

TIA.

ChuckM

Using Thunderbird with Spectrum email (an old roadrunner address). Changed the outgoing server to the following: Server Name: mobile.charter.net Port: 587 Username: Reefside@cfl.rr.com Authentication: Normal Password Connection Security: SSL/TLS Testing connection fails. I have tried different combinations and once in a while I get that the connection is successful, but email sending hangs and never completes.

Dear all,

For aprox. 3 weeks now Thunderbird asks me a short time after startup for a login.

It shows up a dialog with the text : "https://caldav.gmx.net verlangt einen Benutzernamen und ein Passwort."

The problem is, that I maintain several GMX - accounts and I've no idea, which credentials I have to enter :/

How can I find out ( without inspecting or debugging the source code ;-) )

THX in advance and best regards!

So whenever I click on new tabs, it always leads to a redirect notice asking me to confirm if I want to open those tabs.

I want it so that I don't get these notices, but the links I click on just open automatically. I have tried the following settings in about:config based on a few threads online:

accessibility.blockautorefresh

network.http.redirection-limit

A few other settings to that I have turned on and off but no difference.

A lot of the websites are also confusing because they seem to want to turn redirects ON rather than off, so potentially I am struggling to follow the correct information.

Any help appreciated.

I have been using Thunderbird for years with no problems. However recently, Thunderbird very often simply stops responding. Sometimes it just hangs up and sometimes the program bar at the top displays "Mozilla Thunderbird (Not Responding)". If I try to wait for it to respond, it literally hangs for several minutes before it begins to respond again, and often, it simply never starts responding again. It has simply gotten to the point where Thunderbird is practically unusable. All my other application software continues to work with no problems. It's just Thumderbird.

The version number in this submission may not be correct. I can't provide the real version number because of the hangups.

Any suggestions?

Beginning today, I suddenly cannot access numerous websites when I use Mozilla Firefox 151.0.2. Examples include Amazon, and Google, et al. Attempts to do so consistently fail at the point of performing a TLS handshake, when I am advised that "secure connection failed". Kindly refer to the attached screenshots. I have no difficulty whatsoever accessing the same websites when I use other browsers, such as Google Chrome and MS Edge. I previously had Mozilla Firefox enabled as my default browser, but I have had to change this, given these "challenges". Please advise how I can fix this. Best regards and many thanks.

Current Setup: OS: Windows 11 Home (10.0.26200) Firefox Version: 151.0.2 (Build ID: 20260525130955)

Issue:

• Firefox suddenly is unable to connect to any wesbite
• All attempts to browse result in the "Secure Connection Failed" screen
• All other browsers function fine with no network connectivity issues

Exact Display Text:

Secure Connection Failed

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. What can you do about it?

The issue is most likely with the website, and there is nothing you can do to resolve it. You can notify the website’s administrator about the problem.

Attempted Fixes / Things Confirmed:

• Everything mentioned in: Firefox can't load websites but other browsers can

• Relevant about:config values:

* * security.enterprise_roots.enabled -> True

• * security.ssl.enable_ocsp_must_staple -> True
• * security.ssl.enable_ocsp_stapling -> True
• * security.tls.version.max -> 4
• * security.tls.version.min -> 3

• System locale and timezone are correct
• DNS over HTTPS is set to OFF
• HTTPS-Only Mode is set to Don't enable HTTPS-Only Mode
• Restarting in Troubleshooting Mode
• Disabling the Anti-Virus (including the device Firewall)
• Disabling any VPNs or network proxies
• Clearing cache and browsing history
• Clearing certificates from the Certificate Manager in Settings
• Attempting connection with a newly created profile
• Clearing the cert9.db file for Firefox to reset certificate information
• Refreshing Firefox (resetting it completely)
• Uninstalling and reinstalling Firefox (after clearing all Mozilla related %appdata% folders)

Observations

• When trying to mess with the device timezone and see if changing it back to the correct one would "reset" something, after a few attempts of starting Firefox in the wrong timezone and then restarting it after changing to the correct one, for a single session, I was able to browse normally again. I closed Firefox to see if the problem was fixed but it went back to the "Secure Connection Failed" page. Was unable to reproduce the same behavior.

• Tried installing a portable version of Firefox (151.0.3) from Firefox Portable .

After installation, the first session works perfectly fine but after I close the session and restart Firefox, it gives the same "Secure Connection Failed" message.

• * Reinstalling the portable version in the folder, gives the error from the get-go, not even the initial post-installation session works but installing in a different folder works fine for the first session but all subsequent restarts (sessions) of the browser give the same error.

I've been seeing a doubling of *some* incoming messages, where a duplicate message comes very soon after the first one. For example, two incoming messages were received at:

Sun, 07 Jun 2026 14:03:10 +0000

Sun, 07 Jun 2026 14:04:31 +0000

So the second message came in about 1 minute and 21 seconds after the first, and not because of anything I did (as far as I know). But then that was it, no third message came in.

This isn't really a bug, as nothing is harmed, just a repeated message. Any thoughts would be appreciated.

I transferred my Win 11 T-bird system to a new Win 11 computer using the T-Bird instructions re Profiles etc. The system transferred and operates on the new computer, BUT the last six years of e-mails and my current address book and calendar did not. The calendar that transferred was from 2014 to 2020 and the addresses were also from 2020. The current email addresses and up-to-date calendar didn't transfer. How can I make sure my current data transfers. I still have my old computer with T-Bird installed?

Mozilla has been bragging about the free built-in Firefox VPN for months now. I still don't see it. I'm on the latest release (151.0.3) but I don't see any way to access it. I know they've said it would be a phased rollout but it's been a long time coming already. Am I doing somethin wrong?

Hello. Some email addresses are no longer being delivered and are not appearing in my spam folder.

This started about three weeks ago with just one address. Now, I know of at least two.

Emails from these addresses that I used to receive and delete have also disappeared from my spam folder.

Does anyone have a solution?

I can not seem to find the button to open a saved, closed tab group. I have googled, and there seems to be a lot of people with the same issue. However, None of the information given under those forums provides me with a clear, easy solution. Please help.

Last week I started getting the attached pop-up

I don't use Calendar on Thunderbird (as it does not sync ) Not sure why this has started ..... I have tried putting in password and ticking the remember box - but it still keeps popping up.

Malwarebytes is picking up and blocking an outbound connection request from Firefox - www.highperformance.com. Anyone else experiencing this?

Can`t install on my account [edited]@hotmail.com I just create yesterday. I can read outlook program. There is something wrong I don`t know what top do. Therese Driscoll# * Numbered list item