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Thunderbird causes my machine to 'hang' from time to time,

1. often for up to a second and usually a number of times in quick succession on each ocasion. Sometimes this happens frequently - say every 5 or 10 minutes - sometimes only after an hour or more since the past occurrance.

2. My machine hangs completely - nothing will work, mouse, keyboard, sound, other apps etc. If I happen to be typing (into any app - including Thunderbird - when this happens, input ceases, the cursor freezes and - if the problem persists for a second or two, Windows reports "[app] is not responding"

3. I cannot be certain, but I believe the problem occurs whilst messages are being retrieved.

This is a very serious problem as it means that I can never leave TB running as the problems it causes are not acceptable.

4. This means I cannot deal with incoming messages without periodically re-starting TB - which is an utter PIA.

I am running Win 11 Professional on a 2-year old machine with 64 Gb of memory. I have run TB in Troubleshoot mode, I have confirmed that the problem occurs regardless or whatever other apps are running (or none) and I have proven conclusively that no other app causes any kind of similar problem.

Looking forward yto hearing if others have had the same issue and what can be done about it.

I find that my desktop browser firefox is very slow or doesn't work at all on a lot of websites like amazon or fortnine.

My internet connection and computer are not the issue: 270Mbps (wired connection) Processor AMD Ryzen 7 9800X3D 8-Core Processor (4.70 GHz) Installed RAM 32.0 GB (31.1 GB usable) Graphics card NVIDIA GeForce RTX 4070 Ti SUPER (16 GB) Storage 3.58 TB of 10.92 TB used System type 64-bit operating system, x64-based processor (Windows 11)

My old PC and my mobile phone runs these website fine.

Sometimes the website will work for a moment, but stop and just load for ever after I open a new tab or clink a link. My task manager doesn't show any ethernet usage despite the tabs indicating they are trying to load. Refreshing the tabs does nothing and no matter how long I leave them they don't load. All my drivers, OS and programs are up to date. I have disabled my enhanced tracking protection and I don't have any adblockers. I have tried using the CMD "ipconfig -renew" and using ccleaner to clear out my cookies and cache but, nothing seems to have any lasting effect.

I am losing my mind trying to fix this. Why can I not browse the internet on my PC?

Any help on this would be amazing and much appreciated.

Sincerely, Calvin

I have Thunderbird on the old computer. For twenty+ years I have read the instructions for moving it to the new computer. i cannot understand/am not at all confident in my ability AND I have only ONE keyboard/mouse. I have to move it from one computer to the other to operate them.

Right now all email is on the old computer, no email is on the new computer. No email has ever been on my cellular telephone. One set of periforals - keyboard/mouse.

I DO have the Bravura, the Plugable transfer cable and accompanying software, and many other things came across, but not the Thunderbird.

I want to do the move/installation correctly so that not one stored email is lost or corrupted.

I need help.

Gentlemen, isn't your browser using a lot of RAM? I've been freaking out about it in recent years. That's only with 25 tabs open!! Despite the fact that the system was installed just a day ago, without any tweaks!!!

Neither my wife nor I can access email on our respective PCs. This has been the case for four weeks. We can access email by our Android phones, but we really want to use our PCs. I've tried to resolve the problem and failed. Previous to this failure, I had an account with BT but this was transferred to EE. When I attempt to log in to my mail account, I receive the message "Could not connect ... :the connection was refused". I can also add is that in my Account settings, Outgoing Mail server I see a message "Connection to server mail.btinternet.com:465 failed."

recent firefox update can no longer copy and paste when creating a blog post in Squarespace, I have been using squarespace for around 15 years for my websites and I have never seen this issue, Firefox 15.1 installed and all of a sudden when trying to create a blog post in Squarespace, when I right click a text box pop up and it no longer says paste so I can no longer copy and paste text - this is more than a little annoying, you will not be surprised to know that I am now using Chrome to create my posts, there is no issue in chrome. I am a firefox geek! how can i solve this problem, I just did another update from Firefox, the issue remains I have been using computers for 40 year so I am not a novice but software glitches, I am lost

Hi!

We have a intranet site that works in Edge and Chrome without issues with the site added to "internet options". But for some reason we are getting 401 Unauthorized when trying to access it from Firefox. I have tried adding the urls to: network.automatic-ntlm-auth.trusted-uris network.automatic-ntlm-auth.allow-proxies: true network.automatic-ntlm-auth.allow-non-fqdn: true network.auth.force-generic-ntlm: false network.auth.force-generic-ntlm-v1: false

Ingocnito mode , same error. I have tried disabling all plugins. Disabled DNS over HTTPS.

HTTP/1.1 401 Unauthorized Server: Microsoft-IIS/10.0 WWW-Authenticate: Negotiate X-Powered-By: ASP.NET Date: Mon, 25 May 2026 08:15:41 GMT Content-Length: 0

Regards Rasmus

I have followed the instructions that several people give to transfer my existing Thunderbird installation to a new computer where I have just installed Thunderbird. That is I copied the Thunderbird folder and put it in the Roaming folded found in %appdata%. Both computers are on Windows 11. When I open the new Thunderbird, it does not recognise it. Furthermore, in Help>Troubleshooting information>Profile folder when I click to open the folder, it looks for a folder that is not in my previous Thunderbird installation: qr19mupe.default-release instead of the one that came with my imported Thunderbird folder. Has this happened to anybody and found the solution? Can anybody help please?

Hi,

I need some help! Thunderbird used to have archive settings in which I could choose to save my e-mails locally in my archive folders with 1 file per 1 email and not everything that's in a folder saved to a single file.

How can I get this back? Is there some hidden settings that can be accessed to get it done?

I need every email in one file! I'm going nuts trying to sort years of e-mail duplicates. If I can have a file per message, then I can at least use my PC duplicate file program to compare file content and find the similar ones. But with everything of one folder in the same archive file I'll be cursed to have to manually go through thousands of e-mails by hand! So if there is a way to return the previous archive format (*wdseml files??, it seems?) then I want to know how to set that setting.

Alternatively a local folder duplicate e-mail cleaning tool? There used to be some but I couldn't get it to work now!

i have a problem in the connection we need to have remote session

• Client : Mozilla Thunderbird (version utilisée) • Serveur SMTP : smtp-mail.outlook.com • Port : 587 • Sécurité : SSL/TLS • Authentification : OAuth2 • Message d’erreur exact indiquant un timeout / échec de connexion SMTP • Confirmation que : o le compte fonctionne en webmail o le service Microsoft est accessible o le problème persiste malgré un changement de réseau (si testé)

Not sure if I picked the correct topic for this...

I had to reinstall Windows 11 on my PC as the old copy was corrupt to the point I could not install updates, even with Microsoft's help. Before I made the plunge, I used Tools -> Export to create a zip file on my D:. After installing Thuderbird on the rebuilt copy, I went to Tools -> Import to recover everything.

About 19% in, I received error "Import failed unexpectedly, more information may be available in the Error Console." I found the Error Console but don't know how top proceed.

Initial messages: module is not a constructor ExtensionCommon.sys.mjs:1679:15 EmptyDatabaseError: "blocklists/addons-bloomfilters" has not been synced yet Database.sys.mjs:19:5 NS_ERROR_ABORT: Password dialog canceled 2 MsgIncomingServer.sys.mjs:923:24

Messages at the bottom of the console: Uncaught (in promise) NS_ERROR_FILE_NOT_FOUND: Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsIFile.copyTo]

   _recursivelyCopyMsgFolder resource:///modules/ThunderbirdProfileImporter.sys.mjs:781
   _recursivelyCopyMsgFolder resource:///modules/ThunderbirdProfileImporter.sys.mjs:772
   _mergeLocalFolders resource:///modules/ThunderbirdProfileImporter.sys.mjs:745
   _importServersAndAccounts resource:///modules/ThunderbirdProfileImporter.sys.mjs:354

ThunderbirdProfileImporter.sys.mjs:781:19 1785523577301 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/26c785ea-2226-4024-9b0e-cf44ce2860f7/first-shutdown/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577301 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 26c785ea-2226-4024-9b0e-cf44ce2860f7: {"isTrusted":true} Log.sys.mjs:722 1785523577302 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/bc5b8fd6-8907-4169-9e98-2c732d265c20/main/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577302 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping bc5b8fd6-8907-4169-9e98-2c732d265c20: {"isTrusted":true} Log.sys.mjs:722 1785523577302 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/01ee7ef8-942d-4fbd-a404-debd99ad5e4d/new-profile/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577302 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 01ee7ef8-942d-4fbd-a404-debd99ad5e4d: {"isTrusted":true} Log.sys.mjs:722 1785523577325 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/1f64b615-ed65-4a65-8853-7bd3e3077b54/health/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577330 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/26c785ea-2226-4024-9b0e-cf44ce2860f7/first-shutdown/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577330 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 26c785ea-2226-4024-9b0e-cf44ce2860f7: {"isTrusted":true} Log.sys.mjs:722 1785523577331 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/bc5b8fd6-8907-4169-9e98-2c732d265c20/main/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577331 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping bc5b8fd6-8907-4169-9e98-2c732d265c20: {"isTrusted":true} Log.sys.mjs:722 1785523577331 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/01ee7ef8-942d-4fbd-a404-debd99ad5e4d/new-profile/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523577331 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 01ee7ef8-942d-4fbd-a404-debd99ad5e4d: {"isTrusted":true} Log.sys.mjs:722 1785523577334 Toolkit.Telemetry WARN TelemetryStorage::_scanArchive - have seen this id before: 1f64b615-ed65-4a65-8853-7bd3e3077b54, overwrite: false pop3.server1.1: NetworkTimeoutError: a Network error occurred Pop3Client.sys.mjs:381:18 pop3.server1.1: SecurityError info: Pop3Client.sys.mjs:441:20 pop3.server1.1: SecurityError cert chain: imap.email.comcast.net; serial# 5F:F9:03:A2:A2:B8:A3:45:AE:17:FE:A1:C9:15:D6:45 <- Norton Web/Mail Shield Root; serial# 2F:61:CC:98:EC:34:F2:43:99:93:5B:E6:A0:A5:DF:E2 Pop3Client.sys.mjs:446:22 1785523697961 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/1f64b615-ed65-4a65-8853-7bd3e3077b54/health/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523697961 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 1f64b615-ed65-4a65-8853-7bd3e3077b54: {"isTrusted":true} Log.sys.mjs:722 1785523697962 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/26c785ea-2226-4024-9b0e-cf44ce2860f7/first-shutdown/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523697962 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 26c785ea-2226-4024-9b0e-cf44ce2860f7: {"isTrusted":true} Log.sys.mjs:722 1785523697962 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/bc5b8fd6-8907-4169-9e98-2c732d265c20/main/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523697962 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping bc5b8fd6-8907-4169-9e98-2c732d265c20: {"isTrusted":true} Log.sys.mjs:722 1785523697963 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/01ee7ef8-942d-4fbd-a404-debd99ad5e4d/new-profile/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523697963 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 01ee7ef8-942d-4fbd-a404-debd99ad5e4d: {"isTrusted":true} Log.sys.mjs:722 1785523947429 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/1f64b615-ed65-4a65-8853-7bd3e3077b54/health/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523947429 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 1f64b615-ed65-4a65-8853-7bd3e3077b54: {"isTrusted":true} Log.sys.mjs:722 1785523947430 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/26c785ea-2226-4024-9b0e-cf44ce2860f7/first-shutdown/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523947431 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 26c785ea-2226-4024-9b0e-cf44ce2860f7: {"isTrusted":true} Log.sys.mjs:722 1785523947431 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/bc5b8fd6-8907-4169-9e98-2c732d265c20/main/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523947431 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping bc5b8fd6-8907-4169-9e98-2c732d265c20: {"isTrusted":true} Log.sys.mjs:722 1785523947431 Toolkit.Telemetry ERROR TelemetrySend::_doPing - error making request to https://incoming-telemetry.thunderbird.net/submit/telemetry/01ee7ef8-942d-4fbd-a404-debd99ad5e4d/new-profile/Thunderbird/153.0.1/release/20260728090639?v=4: eUnreachable Log.sys.mjs:722 1785523947431 Toolkit.Telemetry ERROR TelemetrySend::sendPersistedPings - failed to send ping 01ee7ef8-942d-4fbd-a404-debd99ad5e4d: {"isTrusted":true} Log.sys.mjs:722

I have an image copy of my old installation. Can I simply locate the Thunderbird profile on the backup and restore it?

Each time I open TBird, I get a message at the bottom left of the screen telling me that TBird has deleted X number of messages. I do not want TBird to ever delete any messages. How do I turn this automatic delete function off?

Until recently the folder pane could be sized or hidden via the double-headed arrowed cursor. Shortly after the 151.0.1 update this stopped working. All suggested solutions have not worked. A full uninstall (Revo Uninstall) and completely new profile has not fixed the problem. Folder pane only responds to the menu setting and is only Open/close but no sizing.

This what you said: "Today we’re introducing a free built-in VPN in Firefox, a new IP-protection feature designed to keep you even more private while you browse. We’re starting by offering an industry-leading 50 gigabytes of free VPN-browsing each month." But all I see are the paid options. I want to try before I (might) buy. After all, you constantly preach that we have to be careful & trying to be careful.

As the topic says, the message list turned from the usual dark-mode look, to a full black background after updating to 151.0.

Was this an intentional change? How can I revert it?

Believe my T-bird account has somehow been corrupted. Takes forever to load on PC and always puts new emails in Trash folder. Often does not accept correct password. If I save / backup PROFILE, uninstall T-Bird and delete any Thunderbird folders on PC, if I restore per backup, will I be restoring the corrupted app. Don't want to loose email addresses, thousands of emails and email folder structure. Will a restore work? Thank you. Greg D

PS Version of T-Bird on laptop still puts all new email in Trash, but loads much more quickly, etc.

I have completely cleared relevant history. I am in the UK, so only use Amazon UK. Yet, even within a day of removing all trace of amazon.com, it shows up again in the list of top sites on a blank tab's address bar suggestions. (.com is not in bookmarks, shortcuts, or recent searches, which are the only other selections)

The only explanation I have for this is that amazon.co.uk is making back-end calls to amazon.com and polluting whatever mechanism is used for this list – even though the browsing history as I can see and manage it does not include any references to amazon.com whatsoever.

Please, either:

• tell me how to get the browsing history as shown in the new tab's suggestions to respect the browsing history as recorded and manageable, or
• tell me how I can have control to blacklist certain sites that contaminate the list despite there being no record of them within my browsing history

The only other detail that may play into this; the first time this appeared out of nowhere I suspect was also the point at which the Suggestions from sponsors magically appeared in settings, and was on by default. Ever since then, getting rid of amazon.com has been a Sisyphean struggle, as though unchecking the sponsors option were being ignored.

I have had to replace my laptop and am trying to set up my new one with an existing outlook account on the new device.

It is a Windows 11 device.

I have used the exact server settings etc from my old lap top for the outlook account but get a variety of error messages.

I have explored the use of the Account Hub and also switched that off/on. Same situation.

I attach five screen captured images so far. The first is the version of TB. The second is the window that appears when the account tries to connect and thirdly the small pop up that appears bottom right hand corner of laptop. The remaining two show the server settings and that they passed the connection test.

Other email accounts (gmail & yahoo) have both been set up on the new device and work well.

The account worked on the old laptop and continues to do so. I have set up the outlook account with, to the best of my knowledge, the same settings. The old lap top was a windows 10 device. The new laptop does not have a third party antivirus on it.

I am baffled as to what is happening and what I should do next. Any advice would be great.

I have removed the drive from the computer that will not boot up. I hope to be able to transfer my "profile" to my new computer from that drive. I understand that I will need to have the same version of Thunderbird installed on my new computer in order to transfer my "profile". Since I can't access Thunderbird on my "crashed" computer, how can I know what version I had installed previously? How do I find where to load that version on my new computer?

One of my two outlook email accounts no longer appears in Thunderbird, which says it is authenticated but not connected. This happened suddenly. I can still get the messages by going onto outlook.com. How do I get it back on Thunderbird?