All Products Community Forum

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

hi today thunderbird started showing yahoo popup login and after adding credentials i always get "something went wrong.We could not sign you in. Try again from a different device." Also popup once closed it opens instantly.

i can sign in normally from browser. thunderbird version is 147

is there any fix about this?

thanks for any help

regards

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!!!

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,

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!

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

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."

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)

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.

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.

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.

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?

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?

I am trying to set up a visualization of the columns of the main interface. Here's what I do:

1. Click on the list icon in the top right corner.
2. Uncheck the columns I want to hide. Specifically, From (CB), Recipient (CB), and Correspondents (CB).
3. Apply the selection to all folders: click on the icon in the top right corner, apply columns to.. > folders and its children... > select account > Confirm

These actions produce immediate results. However, the next day or a few days later, when I reopen the program, the column display changes. Sometimes in the main folder (inbox), sometimes in the subfolders.

Is this a known bug? Is there anything I can do to keep the desired column configuration stable?

I have looked at some of the comments about Firefox automatically opening pdf docs. Myu concern is twofold. Most importantly the password in the doc is somehow being overriden; that is a severe security issuen for me. Destroys the whole concept of security. Makes me very uncomfortable and may discontnue using Forefox after more than 15 years. Secondly this caught me by surprise; it only occurred for the first time this morning. How can i overcome this to prevent Firefox from performing merely as a browser?

Cannot send messages. I get an error code:

Sending of the message failed. An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: RBL restriction: Blacklisted by Internal Reputation Service - 73.62.119.4.

This is a recent abberation. I've updated to the latest version of TBird. But cannot understand this message or why I get it. Please help as I forward/send many messages daily.

Thank you

Attempting to install Thunderbird on an additional desktop using same address as my original computer has. That was my question:

Lin answered: Please quote any and all error messages you see, in full, verbatim. Screen shots would be OK.

Who is your email provider?

Have you compared all account settings, not just the email and password?

Here's my answer to those questions: "Authentication error" "probably wrong configuration, username or password."

My email provider is MTA (Matanuska Telephone Association) Yes, I currently use Thunderbird in my other desk top and it works fine.

I'm having so much trouble with Apple Mail and Thunderbird saving my password and I do have an Apple User Defined Password. So, I'm constantly having to input my password. Any suggestion would be deeply appreciated!

Jerry

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?