Thunderbird Community Forum

Subject: Thunderbird 152 – IMAP Junk messages are not automatically moved to Spam (T-Online IMAP) I am using Thunderbird 152 on Windows 11 with a Deutsche Telekom (T-Online) IMAP account. Problem When I manually mark a message as Junk (toolbar button, context menu or Junk column), the message briefly disappears from the Inbox and immediately reappears. It is marked as Junk, but it is not moved to the Spam folder. If I disable the option "Move new junk messages to:", the message remains in the Inbox and is marked as Junk, without the brief disappearance. Manual Move to → Spam always works correctly. Environment • Windows 11 • Thunderbird 152 • T-Online IMAP • ESET Internet Security • Only one Spam folder exists on the T-Online server. Troubleshooting already performed • Created a completely new IMAP account. • Verified Junk settings. • Verified the Spam folder path: imap://...@secureimap.t-online.de/Spam • Manual move to Spam works correctly. • Rebuilt the folder cache. • Recreated folderTree/folder cache files. • Performed IMAP resynchronization. • Tested with ESET mail protection enabled and disabled (no change). • Checked profile configuration. • Verified that the IMAP server directory setting does not change the behaviour. Additional observation The profile contains two IMAP cache directories: • secureimap.t-online.de • secureimap.t-online-1.de The current IMAP directory does not contain local Spam/Junk cache files, while the old "-1" directory still contains: • Spam • Spam.msf • Junk • Junk.msf Thunderbird also displays a greyed-out, inaccessible Spam/Junk folder which cannot be selected, subscribed or removed. Question Is this a known issue in Thunderbird 152 related to IMAP Junk handling or old IMAP cache migration after changing an account from POP to IMAP? If not, which log or additional information would help identify the cause?

PS: The POP account worked correctly before the migration to IMAP. The problem started only after switching from POP to IMAP. Rudolf.weinzierl-landshut@t-online.de

I have used Thunderbird for years and years and never had a problem. The last 2 weeks all of my outgoing emails have been going to everyone's SPAM folders. I have an AT&T email account and I use the AT&T Pop server settings, for the Outgoing Server I have the Comcast/Xfinity settings. I receive emails with no problems, it is my outgoing emails only. I don't know if it is a Comcast problem, an AT&T problem or Thunderbird problem. I have been on the phone with Xfinity for 2.5 hours and still having problems. Any suggestions.

Guten Tag,

Ich hoffe Ihr könnt mir helfen.

Ich benutze Thundebird das erste mal und würde gerne wissen wo meine gelöschten Mails hin verschoben werden wenn wie auf dem angehängten Bild keine Einstellung vorgenommen wurde standardmäßig. Werden die Mails dann direkt gelöscht aus der kompletten Mail-Adresse oder bleiben diese irgendwo gespeichert?

Die Gelöschten Mails sind im Mail Konto nicht mehr auffindbar.

Viele Grüße

Despite my marking messages several times as NOT spam, Thunderbird keeps on and on RE-marking them as spam. And the mails are coming from one of my own addresses, and they ARE in my address book!!!!!

There seems no way that I can stop the beast from misbehaving.

I have 6 email accounts linked to Thunderbird. I noticed today on one of the accounts, along with inbox, drafts, sent, etc., there is now a spam icon. I didn't change any settings or even look at that email account today. This is the only account with that icon and it won't allow me to delete it. All settings between all accounts are the same, just this dang spam fire icon that I can't delete

When I get spam email in my inbox, I mark it as SPAM. It will arrive again in a couple of days. Why does it come into my in-box still? Its marked as SPAM in my In-BOX!

I don't want to keep touching junk email!!! its a huge waste of time. I cannot find the settings on how to make that action happen.

Please advise. If this isnt possible I will unfortunately be leaving your platform after decades of use. Yes I have donated several times over the years. Not get rich money, but it all helps.

Dean

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.

Hi Team, I right click on a message header and select "mark as spam" which then deletes it but it will let another message from the same place in at a later date, is there a way to have the messages I mark as spam go straight to the spam folder?

Thanks, regards Steve

I am new to Thunderbird, and attempting to use it as my email client. So far I have imported my main Gmail account, a second Gmail account, as well as three different Microsoft accounts. There is a duplicate Spam folder on one of the Exchange accounts, which I assume came with the import. There is, however, no way to delete the Spam folder from the original MS account. None of the other accounts has this issue, although when I had duplicate Trash folders on Gmail accounts earlier, I was able to delete them from the original account, which allowed them to disappear from TB. The Spam messages in TB actually only populate into one of the Spam folders. Any ideas what else I can do to get rid of this superfluous Spam folder, please? Many thx for any help!

Please inform me how I can mark senders in Thunderbird as not spam or is there a list of secure senders so their mails will not go to spam folder?

Best regards Magnus Arnason

I want to create a filter to match any of the 20 addresses on my list. Rather than manually repeating the 'add rule' 19 times, I hoped to import all 20 at once.

Creating a filter with 'to' and putting a comma separated list there doesn't seem to work; the addresses won't be matched. I can't find a config file to manually edit in my profile directory for filters, or an extension to create this filter.

My end-goal is to add this 'blacklist' of my old e-mail addresses that have been leaked to a spam filter. These messages already end up in my spam folder by a rule at my provider, but I want to mark them as spam too, so I can sort through the spam folder more easily to find false positives.

Thanks in advance!

I used to be able to copy links from Youtube and send them to people to watch. Now thunderbird is not letting me do that and says it is spam. This is so irritating as my bedridden sister loved to watch the things I would send her. Is there a way around the spam setting?

Just recently, some of the emails I receive are full of messages in red next to almost every line of the email saying that things like "Likely fraud detected" or "Do not trust this website." There is no indication as to what program is creating all these warnings. I have tried to turn off anything I can find in Thunderbird's security settings to no avail. The main source of emails with these warnings is "Beermenus.com" which I have been receiving for quite awhile before this started. Any ideas on what to do

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.