Forum zhromadźenstwa Thunderbird

Hello,

I run Thunderbird 146.01 under Windows 11 Version 10.0.22631 Build 22631... TB pulls messages from a POP Server.

Though I have tried many fixes TB keeps reverting to requiring that I manually run both Spam Sorting, and Filter Sorting, usually after running these functions automatically for about a week.

Might someone suggest a fix that will have some lasting benefit?

Many thanks,

Lothar

Continuation of my prior post: https://support.mozilla.org/en-US/questions/1516342

Thunderbird has a routine problem with being unable to log into various mail servers. I have four accounts and they all seem to share this problem.

Most recent update: I've tested this in Windows Safe Mode, and the problem has not appeared. Since I can't do any useful work in Safe Mode, it's hard to give it a thorough test, but so far so good. Also, I have removed AVG antivirus because it was redundant. I have seen no improvement since it was removed.

Can this problem be resolved?

I have 2 parallel accounts with the same ISP. As of 2 days ago, whenever I try to send mail, I get this message: “Sending of the message failed. An error occurred while sending mail. The mail server responded: Command rejected. Please verify that your email address is correct in your account settings and try again.” I receive mail as normal. Using the other address with exactly the same settings allows me to send normally as I have for the past ten years! Nothing appears different anywhere in the settings. There were no upgrades that I am aware of. I have since found that I can send from my basic little "travel" computer without issue. Any ideas? BTW, using POP mail settings.

TB 128 stopped downloading messages from 1blu.de on one 1blu account, another is working.

Switching to pop did not help, neither resetting password on server. Going back to imap did not help. Update to 140.7.1 did not help. In 140, TB connects, searching folders, discovers inbox, but no download of new messages. Inbox is abonniert (subscribed?) and messages are set to loaded to TB.

inbox.msf is updated today, the inbox has a date of Jan 26, latest downloaded email as of Jan. 21, inbox is 3GB and writeable.

In itself, the account at 1blu is ok: the release version (146.0.1) can connect and download messages dated until tonight (=right now).

1blu recommended to delete/reinstall the account but that would mean loosing tags and maybe xnotes.

Any help is appreciated. I write legacy and webextention addons for TB and can run test code in the console or in a temporary addon, if needed/helpful.

Thanks, Klaus/opto

Today - 26/01/2026 - Thunderbird keeps crashing for no reason. I receive a dialogue box to either quit or start Thunderbird again and to add to a crash report. I have been doing this all morning - no response. I have gone onto Mozilla Google search to see if there is a problem - nothing. I have shut down and re-started the computer - nothing happens. Please can you respond and maybe give me a customer service 'live' person who can talk me through this. I have used Thunderbird for over 15 years, but this is defeating me. I am in my late 70's and cannot cope with the way your Community site works. Thank you for your help. Hope to hear from you soonest.

How can I retrieve emails I deleted by selecting wrong parameters in the wrong area. I was in Thunderbird > Acct Settings > Synchronization & Storage and saw "Disk Space" settings. Without thinking I selected --> O ... Delete messages more than [ xxx ] [ ^v ] days old and I changed the number to... [ 90 ] days old. Like an idiot, I for some reason thought I was dealing with messages in "Trash"... go figure. So of course I then noticed in my email Accounts... all messages older than 90 days were removed from all of my folders I had set-up. Many of the folders are now blank, empty of emails that I had moved into the separate folders set-up for different information. I've explored tons of solution responses in "Support" but haven't found a solution to my problem. I really need my older emails back... please help! , Ron.

Hello, My SMTP server uses Let's Encrypt certificate. The website with the same domain has no certificate. Thunderbird refuses to connect to my SMTP server. Test connection to the server (STARTTLS) in account settings sais "The secure connection to the server failed" (or similar. I see bg localization). Another server with Let's Encrypt certificate. Test pases. Clicking View certificate shows webserver cert (from DigiCert Inc).

I can't send emails! :)

Regards! Valentin

I exported my contact list from Outlook to a CSV file. I then cleaned up the file to delete all the columns I am not using and now have only first name, last name, email address. When I import contacts from this CSV file, I only see the first name and email address in the address book. How do I display both first and last names and sort on last names?

This just started 4 or 5 days ago ( 2026.1.23 ish). I did not update TB nor make any changes to the account in question (that I'm aware of). The errors show up every few minutes, with a 'beep' sound and notification pop-up showing up each time - is very annoying.

I was running v145 when it started. I saw there was an update to 147 and installed that; same issue. I restarted TB into Troubleshooting mode and am still getting the error.

This is running on MacOS 15.7.3. Hardware is MacMini (2024) with Apple M4 chip.

Generally I still seem able to received & send emails.

I opened Activity Manager and Error Console. Error console doesn't seem to have much (using 'Multiprocess', with Errors, Warnings, Logs, Debug enabled). Activity manager shows things such as:

<my account name>

   Connection to server outlook.office365.com was interrupted.    09:49
   Failed to connect to server outlook.office365.com.    09:52
   Authentication failure while connecting to server outlook.office365.com.    09:58
   Authentication failure while connecting to server outlook.office365.com.    10:03
   Connection to server outlook.office365.com was interrupted.    10:10
   Connection to server outlook.office365.com was interrupted.    10:14
   Connection to server outlook.office365.com was interrupted.    10:20

There was an error or log entry that I was able to find a few days ago that made me think it was Calendar related, but now I'm not finding that message.

Is it possible to add different background colours to the three inbox folders I have now, please? I can change the colours of mail I send (via Composition), but not mail I get. It'd make it easier to prioritise work flow. I've found an old (2020) AddColors Add-On as part of the Unified Folders page but it's no longer supported and Firefox doesn't verify it.

I have been trying for days now to set up my Homail account into Thunderbird. It shows it there, but doesn't download any messages.I have tried every way I can to set it up, but, no joy. I even downloaded a programme suggested on Firefox, but that didn't work either. I also cannot find where to check the SMTP connections. I haven't had any problems with my Gmail accounts, they went straight in.

On first start of Thunderbird in the unified inbox there are sometimes empty messages listed with date of 1/1/1970 01:00.

When I click on any of them to view message, they always just blank empty body with no subject or sender. If I click on any other inbox, then go straight back to the unified inbox, the blank messages have gone.

I recently upgraded from v140-ESR to v147-Release and thought it may stop happening, but it still occurs sometimes.

Doesn't seem to be doing any harm but it's strange behaviour nonetheless, so thought I'd see if anyone else has experienced this or what you guys think could be causing it.

About a month ago my Filter log no longer works, the box is checked to show the filter log. I wasn't too concerned at first but know I noticed some of my good email are being deleted and I can't see what filter is triggering it to stop it. How do I get to log to start showing again?

I had an account gmail in thunderbird I lost it because I had to change the password and did not find to change it in thunderbird. I want to add this account in thinderbird but did not succeed. Can you tell me all what to do, I had always a window of Google that open but I do not understand what to do with it.