Thunderbird Community Forum

I'm dealing with a properly updated 'bird: 140.5.0 (32-bit) running on an equally updated Windows 10 desktop. First thing this morning, out of nowhere, I started getting an "unable to write the email to the mailbox..." message when sending, thus I could send but not save. And then I realized I wasn't receiving either, on all three accounts in my Thunderbird. I stopped everything and focused on trying to fix this. It's been an all-day, losing effort. So far.

I tried the various quick checks and fixes recommended here and there: I'm running the program as an administrator. I restarted the program. I rebooted the computer. I think I have enough disk space, but to be sure I deleted some bloat from possibly overly large files. I compacted, even though the program is configured to do that regularly. I temporarily disabled my antivirus program. I went into my webmail and deleted all messages that have arrived since my Thunderbird stopped receiving, in case one of them was corrupted. And probably some other attempts as well. Nothing has helped.

And now a second, even worse issue has fallen from the sky. Thunderbird opens. The folder list is where it always has been. The number of unopened messages in each folder is there in boldface, as always, but...the folders are all blank and I get the dreaded popup: "unable to open the summary file...." Have I lost my years' worth of carefully curated emails?

I've tried folder repair. I've deleted parent.lock. Etc. Nothing. Nothing. Nothing.

I will be super-grateful for any wisdom sent my way.

I would like to change the authentication method to OAuth2, but it doesn't appear in the drop-down menu.

My Thunderbird version is 140.4.0esr (64-bit). I have all cookies set to allow.

How do I change it to OAuth2?

At startup of Thunderbird, get error related to Outlook which I do not use. Get message - "UserHasNoMailboxandNoLicenseAssignedError"

How do I get rid of this error, has been present since last esr release and expected it to go away with new release - did not. Do I have to reinstall Thunderbird to clear.

Hello:

My Windows Thunderbird has become unresponsive, taking forever to connect to my various accounts. I suspect the problem is with my GMail account--which is not my primary account--is causing the problem, but I am unable to un-sync GMail's All Mail folder.

I was able to get into troubleshooting mode, but TB was still unresponsive.

I have copied the profile in question to my Linux machine, with TB V140.4.0esr, to try to repair the profile, but the problem is recurring there as well.

Is there a way to manually edit the profile file(s) to remove the GMail account from Thunderbird?

Any insights would be much appreciated.

Thanks

DrP

I am able to receive emails with my Spectrum account but unable to send. My SMTP entries are Description Server Name mail.twc.com port 587 Connection security SSL/TLS Authentication normal password When I test the connection it passes and I can see my emails but am unable to send emails and get this message Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mail.twc.com failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again. When I look in the Thunderbird settings/privacy and security the only password entry is for IMAP password. Do I have to have and entry for SMTP password or is it the same for both? If I do how do I get an entry there. If any other information is needed please let me know. Thanks

I want to switch back from the Thunderbird Release channel to the ESR channel but I do not understand the steps. Please help me with the exact, easiest steps. I am running Win 11.

When I open the Thunderbird desktop app we receive this popup error message:

"Unable to establish TLS connection to POP3 server. The server may be down or may be incorrectly configured. Please verify the correct configuration in the Server Settings for your mail server in the Account Settings window and try again."

I have not found any configuration under the account settings to help with this, but if anyone has any suggestions to walk me through this to establish a connection again that would be most appreciated.

Additionally, when I try to send an email I receive the message: "Login to server smtp.cybermesa.com with username centinela failed."

After closing the error message box I received another error message: "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) smtp.cybermesa.com timed out. Try again."

Is our issue then with Cybermesa and not Thunderbird? Or Is something wrong with Thunderbird due to our initial error message we received? Any suggestions is much appreciated.

‘We formerly had our email with Cox Communications, and had used Thunderbird. Cox ended their email and said we should use yahoo.com and we could keep our email address, which is [edited] @cox.net.’ Can we still use [edited email from public forum] @cox.net for ‘Thunderbird’ as well? I definitely prefer Thunderbird!

I've recently started using Thunderbird in place of Microsoft Outlook. I have also upgraded from Windows 10 to 11. Unfortunately, my mailing groups that I used in Outlook did not transfer as groups. I was able to import my contacts as a .csv file and I have now set these out in an Excel spreadsheet. My contacts are now in alaphabetic order so whilst I have the contact data such as emails, all of my previous mailing groups are now mixed together!

Is there any way that I can select either individal enties on my spreadsheet or maybe multiple entries and import them into a new address book?

Any ideas or experience would be very helpful.

I recently installed 145.0, was running the latest esr release before on my Windows laptop.

Now when I try to drag a file into an email to attach it, I get the black no smoking sign. Only way to attach is to use the drop down menu. Drag & drop was working fine in the esr version.

Hi I was using TB 142 without problems. When upgrading to 143 ou 144.B4 I have problems sending mails to all users after some times. Usually the first mails are sent immediatly but after around 10 mails, I have very slow response (varies from 5 sec to more than 1 minute and sometimes timeout). Usually quitting TB solves the problem but this is very annoying. I went back to 140LTS and sems to have no longer this problem. This was tested on many diffrent networks. I am running under Fedora release 42

Thanks

For a few days now, synchronization and opening new messages from a Gmail account configured in Thunderbird have been very slow. I use Thunderbird 140.x, which is regularly updated, and the mailbox has been configured for at least 5 years. Only in the last week has the problem emerged, rendering it unusable. Timeout errors and opening a new message after 2-3 minutes. I've cleared the cache, the database, and re-indexed, but nothing has changed. I've deleted and reconfigured my Gmail account, but nothing has changed. My Gmail mailbox is about 45 GB (I've seen much larger ones without losing performance). I tried installing Thunderbird on a new, clean PC, but the same thing. Extremely slow. Google support hasn't found any issues. Do you have any other suggestions for getting Thunderbird back up and running? Thanks.

I am trying to restore my Thunderbird/Mozilla account, and get the following message:

Access Denied You don't have permission to access "http://login.xfinity.com/login" on this server.

Reference #18.4c0f3417.1765301243.f2c2aa1f

https://errors.edgesuite.net/18.4c0f3417.1765301243.f2c2aa1f

Any help would be appreciated, thank you.

I have an account that I am not aware of having requested. The address is the same as the original account and the inbox appears to also be the same. It does state POP3 after the address. I want to remove this account. How can I do that?

When I tried to delete the account all the emails before today on the POP3 address and the original address disappeared. Is it possible to get the emails back or the recent ones?

Hi, I have thunderbird connected to a number of client corporate Office 365 systems (5 in total). The teams option works fine for 4 of them and is quite usable for chat but one of them responds that the browser is an unsupported version. I use Ubuntu 24.04 and have thunderbird and firefox installed from deb files (and the repos) so both are the current/release versions and overall everything works well so I don't believe there is a systemic issue. All connections to the clients' exchange systems are through the owl plugin. With the one client, as soon as you try to connect to their teams site, the 'Hmmm, your browser isn't supported' page comes up. As I manage that client's office platform, I know I've not made any changes to the back-end settings nor have I done so or had to do so on any of my other clients platforms so I don't think there is anything unusual about the Office 365 side (but am willing to be proved wrong). If I try logging in to the problematic teams site using firefox it works perfectly so I don't believe it is firefox being an issue. I have deleted and re-added the account. Has anyone else seen this and got it sorted, and if so how please? Many thanks, Scott...

I use the email address [email 2 removed]@interia.pl. The account is configured in Thunderbird on a Lenovo laptop. The laptop is protected by ESET Smart Security antivirus software. As recommended by Eset, I added ESET VPN to my protection. After enabling ESET VPN, the address doesn't configure. It requests a password. I receive messages that the server is disconnecting. Other addresses work. Disabling ESET VPN causes the address to work. This problem doesn't occur on my other Outlook email client. I would appreciate your help in resolving this issue. Sincerely, Paweł Jędrzejewski

Hi everyone - and big thanks in advance for considering my request: I have/ had windows 11 on my old machine and windows 11 on my new machine; because my 'old computer' is not running anymore at all (liquid damage), I can no longer start Thunderbird and follow the 'export tool function' (https://support.mozilla.org/en-US/kb/thunderbird-export) and thus can only do the manual transfer (https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer); I didn't think that I would need to go through the export tool steps when I saved the Thunderbird profile folder regularly as backup on the cloud; yet when I started Thunderbird on my new machine following the above steps by moving the Thunderbird profile folder manually, the result is that - although Thunderbird is 'running' and the mailbox is functioning properly - the key folders are empty (i.e. the sub-folder structure is completely lost, in fact there are no individual emails at all); the issue seems to be that the size of the Thunderbird profile folder is too large (the "Profiles" folder has a size of 20.5 GB) for doing this transfer via copy & paste of the Thunderbird profile folder from the cloud (I also tried USB) to the new machine; I understand that the size issue via the manual transfer could be 'overcome' just by starting Thunderbird on the 'old machine' and following the above steps explained under mozilla support; yet that's no longer an option; what could I do please?

Unable to add my Mailfence email account to Thunderbird deb install on Ubuntu 24.04.3 Set Up Your Existing Email Address in Thunderbird returns " Thunderbird failed to find the settings for your email account" yet my web mailfence is accessible