Thunderbird Community Forum

When I start Mozilla it checks for new mail. It always says no new mail. When I click on get messages if there are any new ones I get them downloaded. Why doesn't the first check find new mail as it used to? Thanks

Drag and Drop attachments to the desktop stopped working again with Thunderbird 145. Steps to reproduce: You receive a mail with an attachment. You drag an attached file from this message and drop it onto the desktop of your Mac to download it. The attached file is not saved to the desktop (or any other folder I tried). This is on MacOS 26.1 MacMini M4. Please fix asap.

Thunderbird can receive emails but I cannot send them. I get the error message per the screenshot below concerning SMTP.

I have a MacBook Air with Mac OS Sequoia 15.7.2. The error started yesterday (21 November). Just finished conversing with Optus support and they say that it's not at their end: webmail works okay, can receive email and send it (will note there was a brief hiccough earlier today when could not send from webmail, but okay now). All settings as recommended (port for incoming server actually different from what Optus recommends, but when I changed it from 995 to 110, Thunderbird stopped being able to download emails, so changed it back again. Port for outgoing is as recommended, 25.) I tried lowering security, as suggested by Thunderbird help list, and no change so restored it.

I have the latest version of Thunderbird for Mac, 145.0.

My partner, who also uses Thunderbird, cannot receive emails either. He has an older Mac running an older OS.

I have included two images, the second one showing details of selected server. When I clicked 'fetch certificate' it failed. Does that signify anything important?

The error console shows a lot of information, which of course I cannot understand, but can screenshot some of it if that would help.

No firewall, no virus protection, no VPN.

Any ideas as to what might be going on?

I must be doing something wrong. I am new to thunderbird, migrated from Eudora since I can't send mail with Eudora anymore.

I tried to configure Thunderbird as much as possible like Eudora, but ... it doesn't receive nor send mail. On the surface it looks fine, it seems thunderbird logs into the server, it seems it sends mail and checks for new mail, only I don't receive anything, nor send anything even though it looks it does. So what am I doing (or is going) wrong? (I can still receive mail with Eudora and today I checked and received 54 mails, none with Thunderbird)

I have been using Thunderbird for months on my new computer. Last night when I brought it up, a new screen said "Unable to Connect" followed by good information like check the network connection, firewall, etc., make sure Thunderbird is permitted to access the web. Plus, the PC bubble communicated "Authentication failure when trying to connect to server imap.comcast.net".

I have checked everything (looked around) and all seems fine. However, I am a "senior" and maybe I missed some communication along the way. I am getting emails on my iPhone and on the Xfinity website, but Thunderbird is not connecting to the server now. Do I need to change any settings?

Thunderbird was sending and receiving just fine until a couple hours ago. Now, I cannot send anything to anyone - including my email provider. The message is: "Outgoing server (SMTP) error. The server responded: (C18) RBL restriction: Blacklisted by Internal Reputation Service" I verified all the settings (though I changed nothing prior to the problem) and all is correct. I've checked with tech' support and they verified that my address does not have a Blacklist. I've restarted the program and restarted the computer. I've also donated several times to Thunderbird. Before I change clients, I thought I'd see if anyone had a fix for this. Thanks, D

Three weeks ago I attempted to migrate my TB profiles from a 2014 mini-mac to a 2024 mini-mac. I thought I did a better job of backing up my profile using CCC than I actually did. In the migration to the new Mac I lost all my subfolders from the last 20 years. Apple created a new Profile and 2 restoration Profiles on the new Sequoia based mini-mac. I wasn't familiar with these and panicked. I copied those files, took them back to the original mac and tried to follow Toad-Hall's method of restoring the subfolders recommended to bmack1 on 23/11/22. However, I failed to carry out the step of going up two levels in the path of the Library to copy the entire "Thunderbird" file and only copied the Largest restoration file. This in turn, "contaminated" the 2014 original Thunderbird mail profile and only an Inbox and Trash subfolder remained. Today, after 3 weeks of searching and reading the generous contributions of this community, I came across a post explaining that the "sbd files" will show the subfolder headings I created in the original sought after Profile. And I found it!!! My problem is I have re-read Toad-Hall's method of re-installing the original Profile and tried to carry that out to the letter by placing the old Profile within a Thunderbird folder and switching it with the current one. But it's still listed as the "Restoration qqg...file" and probably shouldn't be, but I don't want to go any further and risk losing it because I feel I almost have it. So any guidance would be greatly appreciated. Thank You.

I've got 2 PC, both on the same version of W11 Home and TB?

On my PC that was install in 2020, I can see on each folder and sub-folder unread mail, total mail, and size of that folder (see uploaded image). On my wife's PC, installed in March of this year, only can show the total mail and folder size?

I've Googled how to do that and of course there is no such steps I can do?

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To show the unread message count in Thunderbird's folder pane, click the three dots icon ( ...) at the top right of the folder pane header and select "Folder Pane Columns" or "Show total message count". Some versions may also allow you to enable this view by right-clicking on the folder pane header and selecting "Folder Pane Columns," then choosing to show "Total" and "Unread".

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Right off the bat, no "Folder Pane Columns"???

I suspect somehow this was removed from TB, so new installs this year can't get to it?

I can't even get to that on my PC from 2020 to turn them off?

Is/was there another way? Doesn't seem I have an ADD-ON to do that and I can't locate one that would do it?

Is there an answer to this or is this just the way it is (not)?

PDF filter doesn't work

Trying to refine my search to get only emails with PDF files attachment, only get an empty list when mails with PDF are in the base for sure.

Step by step with screenshots here attached sorted by A, B, C.

A - Basic search with "pdf"

     => 480 attachments files in emails 

B - Filtering A search to get only mails from year 2025

     => in 2025 only 27 emails with attachment - We see in the list result some emails with PDF files attached to it.

C - Trying to get only emails with PDF types attachment, clicking on the top left filter get nothing

      => It's a bug i guess.

Ubuntu 24.04.3 LTS Thunderbird 140.4.0esr (64 bits)

On 18 November 2025

the new beta mozilla has not copied my folder inbox folders, all past emails are gone. I want to revert back to the old system but it wont allow, and I have tried to import the old folders but that has not worked, all it has done is create 2 more copies of local folders (twice). Please help as the old emails are important.

I want to block a sender. The advice on line is to right click the email and create a filter. When I right click the list that appears has no option to create a filter.

How do I block an email, please?

My Thunderbird mail, which has been set up as POP until now, started giving this message yesterday morning: "The connection to the server mail.munkebo-borger.dk was reset." After that, it no longer downloaded any mail from the server. I have now switched Thunderbird to IMAP, and everything works fine since then. But what is the reason that it will no longer run POP, which it has done for several years? Best regards Tommy Jeppesen

Hi, I have the latest Thunderbird on Win10, HP laptop. It all worked fine until a week ago when it started to lose passwords. We have Telia Sweden as provider. I have changed the passwords both in the Telia account and in the Thunderbird account. But the passwords continue to be lost meaning that Thunderbird ask for my password over and over again. Despite the fact that I enter it and clicks to have it stored. That does not help at all. What to do? Leave Thunderbird? When using the Telia webmail it works fine. How to remedy??

I was trying to change the time emails are kept on the server so I went into "Account Settings" and now Thunderbird is locked onto this page. I get a "Mozilla Thunderbird not responding" message when I try and click on anything and I can't get out of this page nor access my Inbox. I've tried starting Thunderbird in Safe Mode which didn't work. I then uninstalled and reinstalled the latest version of Thunderbird but when it starts it goes straight back to the frozen "Account Settings" page. I've checked my profile and there is a new profile that was created with today's date. There is also a profile from June 2025. If the old profile contains all my emails and folders up to yesterday, that would be OK.

Hey, after I opened Thunderbird earlier today, all my public keys and my own private keys have simply disappeared. Thunderbird says it can't find my private keys. I didn't change any settings. What can I do?

J'ai dans mes carnets d'adresses Address Book récupéré par Carddav il est marqué comm carnet par défaut. Lorsque je crée un nouveau message, il n'apparait que très burèvement puis est remplacé par un autre carnet. Comment faire pour qu'il apparaisse tojours por pouvoir slélectionner mes correspondants ? Merci de votre aide.

I am getting the following error message in Thunderbird. Unable to download email to mailbox. Please make sure that the file system has write permissions and that there is enough disk space to copy the mailbox. Write permissions are available and there are 735 GB free.

So I have a self hosted Exchange and I have no problems using it from apps like Google Mail, Outlook and such, plus I can login directly to its .../EWS/Exchange.asmx through a browser. However, when trying with Thunderbird 145/Linux, I always get that username or password are incorrect, but it doesn't tell me exactly what went wrong and how it tried, so I'm in the dark why it is happening. Note: exchange's url is on a different domain than my account.

Basically it's either this message: Authentication error.

Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIMsgAccountManager.createIncomingServer]

Or similar if I try to get message from inbox.

Also weird things happen during configuration, like attached image (note that I've tried different URL permutations)

TLDR; how do I diagnose the issue, or ever better, how to connect? TIA