I will try and make this short and sharp, but like many seamingly simple questions, it touches a vast array of information that collectively makes for an answer. Just as a simple question "what colour is the sky?" is completely misleading in the complexity of the answer, if your result is to be anything but black.

Thunderbird uses a lot of shared code with Firefox. Mozilla have ripped out great swathes of that code and continue to do so in their project quantum ( A pursuit of speed if I understand it at all). This process has been going on for some years, and will ultimately see the entire Thunderbird user interface replaced to "manage" the changes .The Thunderbird community is a very small one, especially at the sharp end where code is written. We simply can not keep up, nor accept responsibility of ongoing maintenance and security on a huge code base that Mozilla is removing, so the internals must change to at least partially match those of Firefox.

That is where the issue really get complicated though. What people want to do in add-ons for mail are very different to what people expect for a web browser, likewise compatibility with chrome in web extensions is not included in our goals, it is not important at all to a mail client. So the Thunderbird team have chosen to adopt what we are calling mail extensions. They are something of a hybrid of the original add-on environment which provides access to things like the local file system for saving attachments and a mail centric set of programming interfaces based loosely around the web extensions process.

So why did none of your favourite add blockers not fork their projects to cover both the mail client and the browser. You would have to ask them, but I will offer a couple of observations;

• Mail intrinsically does not have advertising in the same way as a web page. That is you do not get a row of adds down the side of your mail in Thunderbird as you do in say yahoo. When I log in a get advertising everywhere.

• EMail bodies in Thunderbird can not contain scripts or flash, so the annoying elements of advertising on the web are not present (you can make a Gif flash, but that is 20 year old advertising, not current stuff.

• Thunderbird blocks remote images, so the marketer must bundle adds with the email when they send it. This also is a very uncommon thing, unless the whole purpose of the email is to advertise the sender, and add blockers are not going to fix that.

The primary use of add blockers in Thunderbird were in the RSS feeds where web pages are displayed. But this is a niche part of what in reality is a niche mail program (more than 80% of folks us web mail, not a mail client and only a minority of Thunderbird users use RSS feeds, even if I am one of them). So it could be argued that those creating the add blockers do not see enough demand for the efforts they would expend.

Bobby said

Ads embedded in email messages are still one of the most prevalent ways that computers can get infected with malicious software

That is simply an untruth, according to Kaspersky.

The majority of malware is spread over the Internet. Malicious applications can end up on your computer:

• By visiting a website that contains malicious code. For example, you could fall victim to a drive-by attack.
• By downloading malicious applications that are disguised as ordinary applications.
• By downloading files via peer-to-peer networks (for example, torrents).

Source : https://support.kaspersky.com/789#block1

They further state

Malware can be found in the body of an email or in the attachments. When opening such emails or saving the attachments, you can infect your computer. You can also receive phishing and spam messages in your email inbox.

No anti addware will fix those issues, they are blocking adds, not malware. Thunderbird however minimizes the risk by not allowing scripts in the body of an email so you will not get infected by opening an email. Even if such a script is present it will not run. It is supposed to be technically possible that a remote image might infect your computer, but I am yet to hear of a real live example.

Attachments are another kettle of fish entirely, but an add blocker will do nothing in that instance either. A good anti virus and good practices where attachments are concerned are the best solution there.

Unfortunately, the reality of the situation doesn't fit in without what you're claiming. Scripted ads are, indeed, appearing in emails in Thunderbird, and they are quite intrusive.

And it doesn't address the issue of why you made existing Ad blocking addons incompatible with the latest versions of Thunderbird. If you are, indeed, creating a new Addon framework based on your previous one, then how is it that existing Thunderbird Ad-Block Addons were made incompatible? It would make more sense if the result would be them being basically "grandfathered in" to the new builds of Thunderbird.

Frankly, I don't understand this attitude at Mozilla to constantly alter their software in completely unnecessary ways, resulting in addons being constantly broken. Thunderbird was once the best email client available, but they've caused their own software to drastically drop on the Usability and Compatibility scales. It was perfect as it was; why the constant mania to change it — especially when most of the changes are for the worst, not the better. It's almost as if they're punishing both their users and their addon makers for using their software.

Users use add-ons at their own risk - me included.

Software (in this case Thunderbird) doesn't and cannot stand still - for competitive, security, stability and many other reasons the software MUST evolve, and not always in ways that can be made backward compatible. And so when you install an add-on you put yourself at the mercy of the author as to whether or not they update their add-on.

For better or worse, it has been the case for decades.

Bobby said

Frankly, I don't understand this attitude at Mozilla to constantly alter their software in completely unnecessary ways, resulting in addons being constantly broken.

Frankly I don't understand the need for add blockers in email. So I suppose neither of understands the other. However software evolves, my handy copy of Nortons Utilities that I spend big money on back in 1990 does not work any more at all. Nether to those expensive copies of Microsoft office, Adobe, Microsoft Visual studio, Word Perfect or any of the other old software I purchased in the past.

I could say the same about my car. The one I purchased years ago would no longer be able to use the leaded fuel it used, nor would it pass the new polution tests. SO it would be off the road.

We all like stability. The reality of life in the modern world is that stability is death, either in the software world or any of the manufacturing industries or even in life. If you to no evolve and progress you simply get left behind and become another failed company.

As I told you before, Thunderbird does not run scripts. This is not one of those convenient alternative facts I keep hearing. This is a real one. It does not matter how you twist it. The fact remains. Scripts do not run.

I don't care what you say; what I've clearly observed with my own eyes says different, and the danger of ads in emails is a well-known, well-documented phenomenon.

So your alternate "facts" don't fit the reality of the situation.

Clearly you are not seeking support, you are simply try determined to hold your position and repeated post untruths and say you see them with your own eyes.

So instead of wasting time here convince me, click the forward as attachment button on one of these email you are seeing with your own eyes and send it to matt_Au at GMX.com and I will see it also with my own eyes. Until them, I have no intention of entering further int a discussion that to me borders on the surreal.

But that will not change the facts. Add-ons have changed, they will not be changing back and they will continue to change. If you particularly want addplus, contact them, offer them a couple of thundered thousand dollars or so and they might think about your request. I really don't know what their development costs would be, but it would have to be in the low to mid six figures at least.

No, I'm seeking an answer as to why Mozilla has done something irrational and opened up its users to unnecessary risk. Scripts aren't the only way that emails can deliver malicious software, and I'm not talking about opening attachments. I'm talking about the well-documented phenomenon of malicious code actually being inserted into image files that are able to use even the limited capability of image-displaying software to deliver said malicious code to the recipient.

And no, disabling all pictures isn't an option. What is an option is Mozilla giving its users and addon developers a break and not constantly disable highly-useful and very safe addons, just for the sake of making it seem like they're "doing something" by releasing new builds that do nothing but disable another set of addons.

None of your responses even came close to addressing the issue, but rather were just sanctimonious techno-babble that wasn't relevant to the issue at all.

Yes, I'm seeking an answer. I'm seeking an answer as to why Mozilla makes it so hard on Addon Creators that it's no wonder that they give up on updating their addons to satisfy Mozilla's insane craving for ever-higher build numbers. It's like it's a competition between Mozilla and Google, to see whose software can have the highest version and build number.

This is an issue entirely of Mozilla's making, and only Mozilla can fix it. And I'm asking why Mozilla is doubling-down on the problem instead of actually admitting it's a problem. Have you actually taken a look at just how few addons there are available for the latest build of Thunderbird? That's not indolent addon makers; it's addon makers sick of your shit and saying the hell with it, and moving off to work on addons and extensions for stable online software that isn't constantly trashing their work.

So, what's the answer to that?

Bobby said

So, what's the answer to that?

Mozilla ceased development of Thunderbird in 2012. So you are dealing with a volunteer community, and quite honestly I have no desire to continue this discussion. I see it as a complete waste of my time. You have not sent me an email as requested, and I really think I know why. Because the advertisements are remote images and you refuse to block remote images. That is not my problem. It is yours.

Perhaps you can find another volunteer to air your demands to. So far you have contributed nothing factual and have left me with the feeling you are a troll.

I really do not care anymore. Goodbye. I am done here.

So, you can't answer my question, so I'm a "troll". I see.

If you're representative of the volunteers working on Thunderbird, I can see why it's losing users and add-on creators like a fatal bleeding wound.

re : I'm talking about the well-documented phenomenon of malicious code actually being inserted into image files

By default Thunderbird automatically blocks all remote content. If you have chosen to allow all remote content to be displayed by default or chosen specific remote content to be displayed then that is your choice and you have to be prepared to accept the risk. Suggest you check your settings. Menu icon > Options > Privacy Recommend you do not select the option 'Allow remote content in messages' click on 'Exceptions..' Do you have anything listed? If yes, then you have allowed those in the list. You can remove them if you wish. click on 'Save Changes' click on 'OK'

Basic Stuff: Do not click on links before checking out if the link really is the link you think it is. Hover over the link and the true link will be displayed in the Status bar'

Do not have the following automatically enabled - only use it when you are sure of the sender. Menu icon > View > 'Display Attachments Inline'

Do not open attachments if you are not certain of the source. Do not be curious, it is not worth it. If you do open one accidentally, then your Anti-Virus product will scan it prior to opening.

If you think an email is suspicious. Delete it and then compact the folder to remove all traces of it.

BTW It is the responsibility of the author to maintain their own software and to keep it up to date with whatever software they claim it to work with. Those authors rely on donations from any user to wants to use their product, so they can afford time and updating of skills to maintain their software. If you use an addon extension then you need to converse with the author to understand the intentions of the author. You should find suitable links on the relevant addon webpage to post reviews/contact authors and some also have links to their own support sites.

And you've driven away all the authors of addons with your insistent quest for ever-higher version and build numbers. It's not their fault; you've frustrated them all beyond caring about Thunderbird anymore. That's why there's so few addons for Thunderbird anymore — you've made it a HOSTILE ENVIRONMENT for addon-scripters.

Now you are being silly. I suppose you expect Anti-Virus products to not stay up to date as well. This question has been fully answered.

This is not the place to vent your feelings about using out of date products.

Thunderbird must stay up to date for obvious reasons. It is the responsibility of other products to also stay up to date.

Check your settings to make sure you are not vulnerable by your own interventions.

Now you are being dense and obtuse. Add-on makers are not professionals; they don't get paid for their work, and Thunderbird is re-updating so fast that before they can get a release of their addon that gets around all the crazy crap they're doing with Thunderbird, Thunderbird has already updated again, making what they're working on obsolete before they can even finish it.

The complete lack of self-observation and self-criticism in the Thunderbird team is their own worst enemy. They have a mere fragment of the number of add-on makers they had just a year ago, because nearly all of them have given up in disgust at the Thunderbird Developers not even giving them a fraction of a consideration and a thought about how their changes are (often unnecessarily) making their addons incompatible.

This question hasn't even been addressed, let alone answered. If you think it has, then you are one of those lacking the self-examination and self-critical skills. The Thunderbird developers are NOT team players; it's their way, and everyone else has to adapt to their constant competition with other email clients for ever higher build and version numbers; and if you think that isn't actually happening, then you're not paying attention.

Thunderbird isn't "staying up to date"; It's "updating for the sake of updating". It's already had a fatal bleed of volunteer workers creating support addons for it, and now it's bleeding users because it's getting less and less user-friendly and customizable.

So thanks for proving that all of the Thunderbird developers don't give a crap about addon developers, or even its own users. You've lost yet another user with your team's smug, superior, "you don't know what you're talking about" attitude.

And I won't be the last you lose.

You have repeatedly made this a topic for something other than "support". You have been told this in not the place to vent your opinions or evengelize about.

You clearly are not informed about Thunderbird or it's governance but you have persisted. I am locking your topic as you are not seeking support. If you want to retain privileges to post in this forum, please keep yourself to support issues in future. This in not a place to debate policy or your feelings about the product or those supporting it.