Thunderbird Community Forum

Thunderbird is set as my default email client on my desktop Windows 10 in the default apps and it's set in the Default Programs control panel but when I try to send a document on my desktop to mail recipient, a message comes up saying there is no email program associated to perform the requested action. It is set in Thunderbird as well as the default mail client. Cortana is no longer accessible on Windows 10 on my pc. Thunderbird is set as the email client in the registry settings, I have only a few Startup programs running on startup and cleared the cache in Thunderbird so I don't know what else to do to fix this?

Whenever I go to delete just one email in Thunderbird, every so often it will also delete the email that comes after it. So I have to go into the Deleted Messages folder and move the email back that I didn't want to delete. My Thunderbird stays updated automatically so that is not the issue. I've cleared the Thunderbird cache many times and that didn't fix the issue and my IMAP folders are synced that I know of but not sure about all the folders and not sure how to do that. I didn't have any issues with this until several months ago for no particular reason I can think of. I really don't want to uninstall and reinstall Thunderbird if I don't have to, if there is another fix if anyone has a solution. Couldn't find anything online except for the steps above I already did.

In the last two weeks I have been collecting reminders that can't be dismissed and today I got a new one that is for next Sunday.

They are all birthday reminders, some from contacts, and some from entries straight into the calendar in Thunderbird. All of them are in the calendar in Google tied to my email address and when I check their details, it says they are created by an "Unknown Organizer."

I've tried to delete them in Thunderbird and in Google Contacts via the web -- they won't go away.

Thoughts? I've been using this for years and this is a new problem.

I am on Windows 10, everything is updated to the latest including Thunderbird.

EDIT: it was an add-on. Issue wasn't replicated in troubleshooting mode.

old post: Yes, I have the account setting on for including signature in replies. It only seems to happen when I use the Reply button that's on the bottom-right -- the biggest one, at the bottom of the thread. When I use that button, a field appears below the thread, where I can type my reply, but my signature isn't there, nor is it included in the message found in the Sent folder. When I reply to an email individually, a new window opens with a field populated by my signature. So this seems like a bug to me, unless there is some obscure setting for this that I can't find. I am a new/returned user so I wanted to check in here first. If others think this is a bug, I'll go through the Bugzilla process.

In the screenshot: the reply button at the bottom doesn't include signature, while the reply button in the top right area does include signature.

I have no idea why, but TB is wonking out lately with strange errors?

The folder '[Gmail]/Sent Mail on me@mydomain.com' could not be compacted because writing to folder failed. Verify that you have enough disk space, and that you have write privileges to the file system, then try again.

I have a ton of space and have not changed anything on the PC?

Any ideas?

After updating Thunderbird to version 139.0.2 Thunderbird can't connect to my E-Mail provider! Getting error massage saying “user name or password are wrong!” It happening on my PC with windows10 Pro and the same on my laptop with windows 11 Pro. On my browser or my mobile, I can connect without any problem to my e-mail provider. After consulting my provider, his suggestion was to try installing my account again. I did but it didn’t work (same error) I tried installing older version which Thunderbird was functioning on. It didn’t work either. Even that I cleaned my PC from Thunderbird totally. To clear this point on Versions 139.0 and 139.0.1 Thunderbird function as always before. Up to now any Thunderbird update took automatically the existing setting without any problem. Any information how to solve my problem? Thanks.

Hello,

I am using the latest stable version of Thunderbird on Windows to read FTN (Fidonet) echo conferences that are relayed via NNTP (specifically, through Eternal September).

While the message bodies are usually readable, I have persistent issues with:

Unreadable or corrupted Subject headers

Author names displayed with wrong characters or encoding artifacts

Some headers showing as raw MIME encoding (e.g., =?KOI8-R?B?...) or complete gibberish

I suspect the issue is related to legacy Cyrillic encodings such as KOI8-R or CP866, which are still common in FTN systems. It seems Thunderbird does not properly decode these in NNTP headers.

I’ve attached a screenshot illustrating the problem.

My questions:

Is there any way to force Thunderbird to decode NNTP headers using a specific charset (like KOI8-R)?

Are there any config settings, hidden preferences (about:config), or recommended add-ons to fix this behavior?

Is there an open bug or known limitation related to non-UTF8 header decoding in NNTP messages?

I do not face this issue when reading standard UTF-8 NNTP groups or emails — only FTN-derived groups.

Thank you in advance for any advice. I’m happy to help with diagnostics or testing.

Best regards, Vladislav

Hi- Some emails just don't show up in my inbox-I can get those emails on my phone (applemail) or webmail but not in my thunderbird on my mac. They do not show up in junk or trash. it is like they never existed. How do I fix this? Thanks

Not getting any mail on my Android devices. Had to get a new Google account as the old was was very screwed up. I have TWO email accounts: GMail and Outlook. Outlookk account forwards all incoming mail to GMail account, so I should get mail only from GMail, but both accounts are set up in TB anyway. Outlook is set up as IMAP. GMail is set up as POP, necessary for some reason GMail setup (gmail.google.com) told me. Something about keeping message on the server or deleting them. Have an APP PASSWORD for GMail account because TB didn't like the POP account. Set up TB on my laptop physically. To speed up rest of work, I used TB "Export to mobile" on my phone and tablet. That's when the problems seemed to start. Finally had to set up TB on BOTH Android devices, which as far as I know, I did correctly. With that background, why am I not getting email on either Android device? Any help greatly appreciated.

Owing to a price rise in MS Office, I had been looking to move to free software. Unfortunately for email this isn't working. I have downloaded Thunderbird and have tried to transfer my Outlook data there. I started two weeks ago and on average believe the process has been running a few hours a day, for much of the time when I look occupying 0% of CPU capacity, and most of the time not rising above 1%. The import has been stuck at 33% for that time, which I assume means that it imported Accounts and Settings or Address Books quickly and is taking a very long time to import Mail Messages. (It imported the couple of month's worth on webmail quite quickly.) Likely this is owing to the size of the Outlook file, 5 GB. Does this essentially make the transfer impossible? For how large a file could Thunderbird do a successful import?

Hi all, I'm experiencing a problem when I want to send an email with attachment. If I remove the attachment it send the email.

- Windows 11 Pro 24H2 operating system version 26100.4061 - Thunderbird version 139.0.2 (64-bit) - pop up with message: Sending of the message failed. An error occurred while sending mail. The mail server responded: Message refused. Please check the message and try again. - SMTP configuration (see img) - Provider: tin.it

Please help me Felice

Thunderbird is not synchronizing with Mailfence. My other email accounts (Outlook, Gmail) work fine. TB connects to them, downloads message headers and displays the number of messages correctly. With Mailfence, the messages stop at "connected to imap.mailfence.com" and stalls there. The message disappears after a few seconds and nothing else happens. This happened this morning when I first launched TB. I then got an update to 128.11.1. No change. I did receive the Windows Update 2025-06 Cumulative Update sometime overnight prior to launching TB.

Hello,

Scrolling vertically with mouse-wheel in Thunderbird is uneven and unstable, while scrolling in Firefox* is perfect. (*or any other program) What could be wrong?

Thanks, Mark

Issue 1: When using Shift+F5 to Get All New Messages: This command used to go through my accounts within several seconds; but now this can take several minutes. What changed to cause this?

Issue 2: I have one account that is having server problems... causing must click popups in TB. How do I exclude this account when using Shift+F5? I've tried Unchecking the boxes for "Check for new messages at startup" and "Check for new messages every xx minutes". And one help result suggests "Disable immediate notifications: Uncheck"; but I do not see such a setting.

Recent new system. Previously used Office Outlook and backed everything up to a PST file. Found I couldn't import into Thunderbird, needed to install Outlook first and import it there. Did that. So I have an Office 365 Subscription active and have Outlook active. Now I'm trying to get those messages to Thunderbird, but when I go to Import and select Import From Outlook I get a red error "No profile found" and can't continue. Is there something I need to do regarding Outlook for Thunderbird to recognize it?

Whenever I want to print an email the print preview doesn't show, it keeps displaying a spinning wheel. Printing also doesn't work (as in, I press Save, enter a filename and press Save; the dialog closes but no file is generated).

I already tried the Troubleshooting information -> Clear saved print settings, but to no avail.

Browser console screenshot attached. I'm using Fedora 41 and Thunderbird 128.11.0esr (flatpak).