I-Thunderbird Community Forum

I want to change the default download protocol accessing the mail server from imap to pop3. I went into the account settings & changed the default selection from imap to pop3. But the change does not take effect. Tbird still accesses the server using the imap protocol.

I keep my mail (both sent and received) in local mail folders. My server is gmail, and sent mail is put in gmail's sent folder by default. Every few months, I copy those messages to a local folder, and after I back them up, I delete the server copy.

What to my dismay, I discovered today that only the message headers, and not the messages were present in the local folder, though they had been when downloaded. Looking at the file sizes, I found the sent file to be 0 Kb, and sent.msf 255 Kb, when sent should have been around 60 Kb long.

I have been able to restore the messages from backup (whew!), but I have no idea how then sent file was wiped out. I know I did not do it.

Has anyone else had this happen? Is there a preventive measure I should take?

It has been going on for two days. I tried restarting in troubleshoot mode and it didn't turn on the "Show Password" button. The version of thunderbird I'm using is Mozilla Thunderbird.

Hello,

I am on Thunderbird 150.0.2 for Windows.

I am really suffering here. I need to change the font weight of unread messages. In a non-threaded list.

The default weight I get with my preferred font (Trebuchet MS) is not bold. It is BLACK. When I say BLACK, I mean ultra bold, display font, heading weight. Heavier than the boldest font that even exists in the font family. Thunderbird is creating this ultra mega black font by taking the bold font variant and applying a faux bold effect to it. The result is that the text is so heavy that it takes up twice as much horizontal space as the ordinary bold font variant. This becomes a usability issue because it's not possible to see the date, sender, and subject at the same time.

I have struggled and strived with userchrome.css. Spent hours combing through forums here and elsewhere. I've already enabled the mystery setting in the config editor. I put userchrome.css where it is supposed to be.

I saw a blog post from Mozilla that says "userchrome.css is not supported". What is the actual meaning of this? That it has been actively blocked from working anymore, ever, for anyone? Or that users are taking risks if they create userchrome.css? Why can't developers speak plain language? "Not supported" could mean many things.

When I go to the Style Editor, userchrome.css does not exist there. Which leads me to believe that user customizations are absolutely deprecated and we are not permitted to use userchrome.css.

I tried editing some of the rules in the Style Editor, but could not determine any way of actually storing the changes. When I click Save, I get a dialog where I can **EXPORT** the file. But I can't seem to actually save the changes, because CSS files do not appear to exist in the installation directory. It must be compiled into some library.

This is extremely unsatisfying and super frustrating. Just getting straight answers to things is super difficult, nothing stays the same for more than a couple months, and up to date information either does not exist or is not found by any search engine.

So, please help. I just need to change one setting, the font weight of unread messages. Since Thunderbird is allegedly open source, I thought I would have some ability to make such changes. But the Style Editor doesn't seem to actually be an editor, but merely a read-only interface to precompiled rules? If I wanted to change the font weight of unread messages, would I be forced to compile my own version of Thunderbird? I'm not competent to do that, and it would probably either prevent updates, or the updates would break my changes.

Please help, I am super desperate. I need to see the date, sender, and subject all at the same time. That doesn't seem like an unreasonable ask.

I would gladly pay for an email client that gives me control over my data *and* allows me to control the UI, but apparently that doesn't exist.

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 have a small office with 5 stations to access our one email account and we'd used thunderbird for years, but the lack of integration between the stations meant we changed to Outlook and of course that's a shitshow, so I'm coming back to ask you my self (rather than the tech guy) if there's a way to set up thunderbird so that if desk 1 opens and responds to email 17, that all the desks can see both that it happened and access the responce that desk 1 sent.

We have an IMAP email account hosted locally (as in, not a gmail account, or the like).

I'd be more than happy to pay for a piece of software that I could use. I've used Thunderbird (and Eudora) for decades and I'd like to continue to support it. But moreover, I'd like an email server that doesn't limit my account size (I use email for "corporate history") and one that would allow my individual staff members to see everyone's activity in the email server.

I had most recently (like 6 months ago?) been using thunderbird. My Tech guy said it was the most current version, but I couldn't tell you what it was.

We run on Windows -- most on 11 but a couple still on 10 until I can take the time to set up the new computers.

After I migrated everything to a different computer, 'Local folders' no longer appears in the side bar, so I cannot archive messages locally.

Can some kind person please help me to reinstate it?

When I highlighted the password, it gave me only choices to edit or copy password and the only way I know how to delete a password is to click, "Remove All" and now the "Show Password" button is grayed out.

Hello,

Despite the fact that I have set Thunderbird to display messages as plain text, my needs are not being fully respected. If the message contains some form of markup, presumably HTML, the font size is not what I have chosen. Generally, the font size is smaller than what I have specified in the Thunderbird settings.

This is unacceptable. It is a usability / accessibility issue. If the user chooses Plain Text and sets a font size, they have done that for a reason. Which is accessibility. If Thunderbird ignores the needs of users and applies styling rules to messages, that is a failure state.

Is there some way to actually, truly, absolutely display all messages as plain text in a specified font, weight, and size? If not, what is the protocol for reaching developers so that they can respond to this issue?

Thank you

I upgraded my Fedora nad I think that Thunderbird 149 came with that upgrade. I cannot send mails. Ctrl+enter has no reaction. Downgraded to 148 and everyhing is fine. |<

I was cleaning up my Inbox when I looked at the "Important" folder. I read in a number of places that this is a "Gmail" thing, and messages get in this folder apart from any action etc on my part.

I have a couple questions.

FIRST, are the emails in the "Important" folder only in that folder or are copies in there? I deleted a number of 2 to 3 year old emails that I do not consider important today. The closer I get to this year [2025], the more careful I get.

SECOND, how can the auto-population of that folder be stopped and the folder be deleted? I keep my important emails in designated folders so I can find them.

Thanks in advance

When I tried to delete my old password in "Show Passwords" by highlighting my old password and hitting the backspace key to delete it and every time I click on the background or hit "Enter", it just pops back on where it was so I couldn't correct it without having to click "Remove all" which turned off the "Show Passwords" in "Saved Passwords".

Is Thunderbird not compatible with Earthlink email? I can't seem to get my account added. All of the information is directly from my earthlink account set up information but I just get messages saying the configuration is wrong or password etc. I have checked and rechecked, reset the password multiple times so it is definitely the right password yet it fails to connect. if it simply can't be added I get it and will move on but I have no issue setting it up to other accounts so I just want to be sure I am doing it right and that it is in fact compatible. thanks for any help.

I've been running TB for 10-12 years, generally with no problems. When I logged in on 5/13/26, I saw that Windows had run an overnight update:

    2026-05 Security Update (KB5089549) (26200.8457)

Thunderbird (version 147.0.2.0) was not running, although it had been when I slept the PC the previous night.

Now, when I try to start TB it gives me the crash report dialog. Selecting the Restart option just brings me back to the crash report.

In searching for possible causes, I see that this may be caused by a bad profile. So I open the profile folder with (run) %APPDATA%\Thunderbird\Profiles\ which in my case is:

  C:\Users\<user_name>\AppData\Roaming\Thunderbird\Profiles

This is an empty directory. But if I go up one level to \Thunderbird there is a profile.ini file which contains (actual user ID replaced by <user_ID>:

[Install8216C80C92C4E828] Default=E:\Thunderbird\Profiles

[Profile0] Name=<user_ID> IsRelative=0 Path=E:\Thunderbird\Profiles Default=1

[General] StartWithLastProfile=1 Version=2

"E:\Thunderbird\" is the correct location of my TB installation. In that directory is a profile.ini file that contains:

[General] StartWithLastProfile=1

[Profile0] Name=default IsRelative=1 Path=Profiles/<user_ID>.default

Directory "E:\Thunderbird\Profiles\<user_ID>.default" is present. But all of it's files are dated 2010 except Mail, dated 2016.

Directory "E:\Thunderbird\Profiles" contains the ImapMail and Mail sub directories totaling about 25GB data.

I don't know what the Thunderbird startup process is or if this all looks correct. Can someone give me a sanity check? If this looks normal, what else could be corrupted?

Thanks in advance.