Thunderbird Community Forum

Since yesterday (27 Apr 2026) any and all mail that comes into Thunderbird gets marked as SPAM. I searched online and found people saying that I could reset the junk training filter, so I did this, but incoming mail was still marked as spam. The next suggestion was to delete the training.dat file. Did that, restarted Thunderbird and incoming messages are still marked as spam. The last suggestion was to turn off adaptive junk mail controls. Didn't want to do that because I assumed that it would let spam through. Nope. Turned it off, restarted Thunderbird and two emails from my work came in and got flagged.

I'm running version 140.10.0esr (64-bit) on Windows 11. I am using IMAP to connect to the mail server but it's not running any spam detection software (like Spamassassin). I know this because it's my server and even if it was, no updates have been preformed since the first of this month and this just started happening yesterday. Combine this with the bug that Thunderbird notifies me of incoming mail, even if it's spam (didn't post about this because there are plenty going back a couple of years), is starting to make me look for an alternative.

What is an easy to use anti-spam program for Thunderbird that will allow me to easily mark new messages "block sender" or "block domain?" My e-mail host InMotion and their Spam Assassin does not support quick and easy marking of new messages.

I'm concerned I've got my Junk set up so that TB is not actually learning what is spam, plus spam is not easy to delete.

First question. What is putting [SPAM] in headers before emails arrive? Is it SpamAssassin? I use my own website/email address and my host uses Spam Assassin. My host in addition has their own native Bayesian spam, but that would use *****SPAM***** headers and I never get these.

The problem is this. Most junk arrives marked [SPAM] but doesn't go in the Junk folder, which is the only folder with one-click Empty Junk. So I have filters set up to direct headers with [SPAM] in into the Junk folder.

(i) the [SPAM] arrives in the Junk folder not marked as Junk even though the filters are carefully set up to "Set Junk status to: Junk"

(ii) it doesn't seem possible to bulk mark the contents of the Junk folder as Junk. If I click the flame icon in the header row once, then all the flame icons are switched to not-Junk as expected. But if I click it again then only some, not all, are changed back to Junk. IE completely different from normal all-off/all-on conventions.

(ii) some [SPAM] ends up in the Spam folder despite the filters. This looks like pure filter failure.

The goal is the get all the [SPAM] messages in the Junk folder along with the Junk the TB itself puts there, so (a) I can delete them with a single click plus (b) all marked as Junk so the TB is learning from the [SPAM] emails.

How can I do that please? What am I doing wrong?

Many thanks.

I recently upgraded to TB 128.14 Oesr (64, Win 10). I’m a bit conservative about upgrading anything – as upgrades often waste a lot of time – if not risk justified.

Basically, If it’s workin’ well enough (cost vs benefit) …… well … “don’t fix it” – even though … “if it ain’t broke, doesn’t mean it isn’t sub-optimal”. Here, it seemed worth the risk.

My prior TB version – nope, I don’t remember which it was (is that in a log?) incorrectly identified bookoo normal e-messages as “junk” (junk filter deactivated) wasting a LOT of my time to move them back to the “indox”.

It also – CORRECTLY ID’ed – a big lot of data sucking spam as “junk” (junk filter still deactivated) for my PUBLIC e-address (expected spam magnet) – alerting me of the quantity of (expected) spam I was actually getting (my free Omaha steaks are on the way).

After upgrading (to TB 128.14) I don’t get any, well much of that spam any more (got a couple today) – hurrah (maybe)!! I don’t see it any more. It is gone completely (mostly, ostensibly) and the problem is – I do want to SEE it – all of it – in a “spam folder / directory” nd not in trash– wherever it is – to make sure it is NOT mis-ID’ed as spam – when actually an important message maybe telling me I’ve won the FIFA email prize!

So … “the game is a’foot! Holmes! How can I track down that missing spam – to see ALL of it – to verify it’s identity?

I suspect my hosting company – Hostinger – may be involved – as I did verify, previously, with my previous TB version – that they COULD see into my TB account structure. Can’t find it now, but previous did see MY TB account named “Aviation”. They, Hostinger, said THEY aren’t “moving” anything anywhere – not into “Junk”, anyway. Are they lying (as popular as that has become recently)?

I’m not smart enough to understand DKIM (though I could get that way) just want to see ALL email sent to ALL my e-addresses that didn’t get there – wherever it is (not immediately, I would hope)!

Merci,

Dru

When I click "Empty Trash," the trash is emptied. However, the status indicator (number of emails) remains unchanged until I click the trash icon again. Is there a missing "Refresh" function?

I have turned off every junk filtering option in Thunderbird, globally and for each account, yet the application started and continues to mark nearly every incoming email I receive as possible junk -- even emails from MOZILLA... It is not my ISP, nor my email provider, as they are not filtering junk, either. The banner on the preview window says "Thunderbird thinks this message is Junk mail", so that tells me it is THUNDERBIRD that is doing this. How can I get the app to stop??? There are no helpful conversations in the forum, since I've tried all of the solutions that were presented. I'm about to just delete the app and use something else which is a shame since I've been using Thunderbird for probably 20 years, but I cannot continue if this problem does not stop.

I'm a bit lost with the instructions http://mzl.la/1BsOG2o My thunderbird looks different I don't see a "Trust junk mail headers set by" option. What would be the proper way?

I am on Ubuntu 22.04.5 using Thunderbird 140.7.1esr (64-bit). After the latest update (from 128.12.0+build1-0ubuntu0.22.04.1) the notifications for mail has changed. Instead of just getting a notice, the notice now allows me to mark as read right within the notification (which is cool), but also now I am getting notifications when Junk mail comes in. Not a notification that it's junk, just that it is a new email.

I do *not* want these to automatically get marked as Read when they come in, as I do want to manually review them in case it's a mistake, and leaving them as unread in my Junk folder makes sense to me in order to make that easier. However, I do not want these notifications on each and every mail. If it's junk it should just silently classify it as such, like it used to. However, I cannot find a setting for this. is there a way to revert to the old behavior without rolling back to an earlier version of Thunderbird? Thanks!

Last week my Inbox started showing TWO (2) unread messages, but I cannot find any unread messages in my Inbox. My SPAM folder is also showing two (2) spam messages, but there is only one spam message in the folder.

Starting yesterday, Thunderbird will not let me delete all the junk from my Junk folder. When I right click on it and select Delete, T-bird freezes with NotResponding and I have to restart it. Once I went through and used Delete on the individual files within the Junk Folder. When I restarted T-bird, it had moved all those files to my Inbox - several thousand of them.

Can I simply delete the Junk file at \AppData\Roaming\Thunderbird\Profiles\hxza0a1k.default-release\Mail\mail.aircraftdesign.com? Or would that kill the whole thing?

Any other workaround? I spent 4 hours talking to Network Solutions, they checked all my account settings and said it is all correct.

I accidentally moved a Google calendar notification to the spam folder 1 time and now I can't get TB to stop putting them in there. I reset the training data and created a message filter to catch them but they still automatically go into my spam folder. How do I get these messages to go to my inbox instead of spam?

How the [edited] do I turn automatic spam filtering off? I've literally unchecked EVERYTHING related to junk or spam, but it's still marking every [edited] email that I get as spam. Even addresses in my address book!

I keep getting 30 to 40 messages in my junk folder every day that are not junk or spam. I keep moving them to my inbox folder but many of the same messages keep going to the junk folder.

Hi. Somehow, in Thunderbird Mail, I moved the "Bulk" folder into the "Trash" folder and now I can't reverse that. Some of my mail is going to the "Bulk" folder and I'm forgetting to check that, thus missing emails. Is there a way to move that "Bulk" folder back where it belongs? thanks in advance

Hallo, ich benutze Thunder in der neuesten Version unter Win11 und verwalte 3 Mailadressen darunter. Nun ist mir aufgefallen das auf einmal 2 Spamordner pro Mailadresse angelegt sind aber nur ein Ordner benutzt wird. Wie kann ich die unbenutzten Spamordner löschen ??? Mailadressen als IMAP angelegt 2 Mailadressen unter Seuresmtp.t-online.de 1 Mailadresse unter Web.de Freemail-smtp.de mit Googleübersetzer

Hello, I'm using the latest version of Thunderbird on Windows 11 and manage three email addresses with it. I've noticed that two spam folders have suddenly been created for each email address, but only one folder is being used. How can I delete the unused spam folders?

Email addresses set up as IMAP

Two email addresses are with Seuresmtp.t-online.de One email address is with Web.de Freemail-smtp.de