Thunderbird Community Forum

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.

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

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 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.

I am trying to create filters for all the spam I have been receiving. It mentioned a tools menu for adding additional filters, but I am not seeing a tools menu anywhere,

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.

I recently upgraded Thunderbird from v140.7-ESR to v147-Release and would be grateful if someone could answer some questions.

After upgrading I noticed there are 3 profile folders even though I am the only user of my Win11 laptop.

Profile Folders 92yfgi88.default-esr - 3.654 GB - 2026/01/23 12:50:27 >> My profile jf63jfuk.default-default - 1.533 GB - 2024/06/05 21:27:32 y9efj7q9.default - 47 Byte - 2026/01/23 12:30:15

The folder y9efj7q9.default only contains 2 files - parent.lock (0kb) and times.json (1kb).

1. Can I safely delete profiles I don't use?

2. Why is -ESR still shown at end of my profile folder name? - I thought it would be renamed when I changed to the release channel version.

3. Can I manually rename my profile folder? - I know I can rename a profile using Profile Manager but this doesn't rename the folder.

4. If not possible to rename my "92yfgi88.default-esr" folder, I assume I can just copy it's contents to another new profile folder and tell TBird to start using that?

5. Can I use Windows File Explorer to delete/rename profiles, or must this be done from within Thunderbird?

Also, any idea why Thunderbird Notifications still show as coming from Mozilla Thunderbird ESR, even though I now use the Release version? I've checked Windows 11 System > Notifications and it is still shown there as Mozilla Thunderbird ESR.. Why? and how to fix?

Thanks in advance..

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.

Good Afternoon Theres 2 accounts under the same username.One is working fine and the other one displays the error notification "Failed to connect to server mackie. when I press on inbox. What confuses me is that it has the same names but has different folders underneath it.I need the one that displays the error messages to be fixed.

I tried unticking enable and it did NOT work. Help! I want the stupid filter gone. I have struggled for two years with the junk filter which does not work right. I have done shift J. The filter does NOT learn. A week aog, I saw that I could uncheck enable and that was supposed to stop the filter. That also did NOT work.

Today, an email I forwarded to myself from another platform went in junk. I never wanted any junk filter. It has been nothing but trouble and now I can't even disable it.

Good day,

I have installed the latest version for win64. Every time the software is downloading emails (I use POP3 for gmail), if I am concurrently doing something else with it (e.g. selecting an email with the right mouse button to delete it, or creating an event for the calendar, or just selecting something from the menu bar), the software gets stuck. I then have to kill it and restart, sometimes it takes multiple kill and restart sequences.

I am using Thunderbird from the very beginning o fit, but this issue is pretty annoying. Any advise?

Thanks and BR M

For quite a few months now, Thunderbird has been acting weird. My emails download, I can sometimes open and delete some, but after a short time, it gets stuck on one email and won't open any more at all. I also can't open any menus, but I can change inbox folders, but still only the original email is shown. It's really hard to troubleshoot and try to fix, as I can't get to any of the menus most of the time. This happens in safe mode as well. This is getting really irritating as I've been using Thunderbird for many years, and I'd like to fix it rather than find a new email program.