You say there are no server side filters, but does the provider apply spam filters? Practically all of them do.

https://support.mozilla.org/en-US/questions/1404881

No, the mail server provider does not apply spam filters unless you explicitly turn them on. Mine are off.

I've used Thunderbird for 20 years and this problem only started in the 6 months or so.

Enshittification in the name of security when the reality is it's a loss of usability.

Hi Tim P,

I can imagine how frustrating this is for you. It would be for me too.

Who is your e-mail service provider? Is this problem happening with a server account or the local folders account? Do you access your account from any other client? If you keep Thunderbird closed for a while but access your mail from somewhere else, does the problem persist? (You may not be able to tell.) Do you have more than one account and you are using unified folders or some other presentation that might make it difficult to tell that an account has filtering turned on? When you say that you have no filters, do you mean that no message filters (under the "Tools" menu) are enabled?

One support person on the forum stated that security software and anti-virus software sometimes filter mail. I do not know about that. Are you using such software?

One logical conclusion is that Thunderbird is not respecting your settings. Are any other setttings being ignored? Is Thunderbird acting badly in any other way?

Are you using any add-ons?

As a troubleshooting step, you might try running Windows (are you using Windows?) in safe mode with networking enabled, then running Thunderbird in troubleshooting mode ("Help" menu) and see if the problem persists.

(By the way, "enshittification" does not apply to this situation. It is very unlikely that Mozilla designed the program to filter spam/junk messages when the filter is not enabled, and they certainly would not have done it to maximize advertising revenue or profit or shareholder value. If everything that you wrote is accurate, this is a problem that people want to fix. We're trying to help here. If you provide more information, someone may be able to help you solve the problem.)

While I do appreciate your help and understanding, I worked in computer support for years and you are giving me the "turn it off and on again" level of suggestions.

I'm way past that point -- I'm not using add-ons, filters (in any menu), or high-cholesterol snack foods. I'm using Microsoft Security Essentials for anti-virus, but that suggestion is just silly. Antivirus doesn't effect mail routing! It could warn me about dangerous attachments or quarantine them, but this is regular frickin html/text emails Thunderbird is arbitrarily deciding to throw into a junk folder I can't disable.

I work at the ISP that provides the mail server. It simply isn't filtering my mail because I have admin access and verified it multiple times.

I'm not going cripple my productivity by booting into safe mode and waiting a couple days for Thunderbird to send more time-sensitive communication into junk mail so I can rule out ... what exactly?

You're right, enshittification doesn't apply in this case. But shitty user experience does. I can't turn off a feature that is making the software unusable for my needs.

you are giving me the "turn it off and on again" level of suggestions.

No, I am not. There was a sound problem-solving reason for everything that I asked.

I can't turn off a feature that is making the software unusable for my needs.

It is not a feature. It is a problem that people here could have helped you solve.

but yet, nobody ever has.

this isn't my first attempt.

but it is my last.

One Question and three answers. It might not be you first attempt, but it would appear your profile here does not support the assertion. https://support.mozilla.org/en-US/user/timphrsn/

I'm way past that point -- I'm not using add-ons, filters (in any menu), or high-cholesterol snack foods. I'm using Microsoft Security Essentials for anti-virus, but that suggestion is just silly.

Microsoft Security Essentials (MSE) is a discontinued antivirus software (AV) product that provides protection against different types of malicious software, such as computer viruses, spyware, rootkits, and Trojan horses. Prior to version 4.5, MSE ran on Windows XP, Windows Vista, and Windows 7, but not on Windows 8 and later versions

The forum software reports you to be posting using Windows 10 or 11, and the edge browser on a 64bit system. Neither Windows 10 or 11 run Microsoft Security Essentials they support Microsoft Defender.

Antivirus doesn't effect mail routing! It could warn me about dangerous attachments or quarantine them, but this is regular frickin html/text emails Thunderbird is arbitrarily deciding to throw into a junk folder I can't disable.

How I wish that statement was true. It is not and has not been universal true for a long time now. Many antivirus products think they are SPAM and SCAM managers and make a general mess with their unsupported code injections into the running Thunderbird application. Worst of all is the only interface to mange the code is in the antivirus product, not Thunderbird. But Thunderbird troubleshooting mode stops that rot, so it is excellent as a diagnostic tool.

I work at the ISP that provides the mail server. It simply isn't filtering my mail because I have admin access and verified it multiple times.

Something useful. AN ISP without any form of spam filtering, How quaint. Like Mr Scott telling the computer how to make transparent aluminum. However is your account configured as IMAP or POP in Thunderbird? I may appear banal, but I only appear to see folk here which complaints about spam filtering not turning off that have IMAP mail accounts and spam filtering elsewhere, like their phone.

I'm not going cripple my productivity by booting into safe mode and waiting a couple days for Thunderbird to send more time-sensitive communication into junk mail so I can rule out ... what exactly?

The garbage that most folk have loaded on startup. System optimization software that usually cripples something important, things like CCleaner which routinely cripples Thunderbird by deleting its settings files. Lots of complaints over the years from that.

I know My Thunderbird stops doing anything with junk processing if I disable it, at least the POP mail account do. The IMAP accounts follow the server values, so spam tagged as such on my phone filters back to Thunderbird via the server as such. You however are asserting something else happens, filtering simply does not turn off at all when you change the settings to disable it.

How can both of those things be true? Clearly they can not is how I see it, so I am looking for reasons why your system is unique in that spam filtering refuses to disable, except you say it is disabled.

You're right, enshittification doesn't apply in this case. But shitty user experience does. I can't turn off a feature that is making the software unusable for my needs.

I would like to get to the bottom of why your experience is different to ours, but that requires information, not the offering of statement of semi fact that this thread contains. I have little doubt 6ou are using Microsoft Defender as antivirus, but that is not what you say. So everything you say has to be verified in some way. My junk filtering works. I am using Name Thunderbird Version 140.4.0esr Build ID 20251010020716 On Windows 11 Professional.

I have used (I think) every release version since 2 all have worked as designed with regard to SPAM filtering.

What does you SPAM look like in the JUNK folder? Does it have this icon ? or is is grey?

These are all mail in my junk folder. None of them was placed there by Thunderbird.

My work does have spam filtering, but I have it disabled for my account.

Sorry, I meant "Windows Security" not MSE.

Either way, I fixed the problem: I uninstalled Thunderbird.

As a bonus I don't have to interact with snarky condescending people "trying" to help.

Good day.