CEO of MZLA (the Mozilla entity that develops Thunderbird). One point of clarification, we don't get money from any source but our donors. After years of funding issues, MZLA was created by the Mozilla Foundation and the Thunderbird Council (our community governance body), to provide a legal/financial home for Thunderbird.

Launching Thundermail this year (an email service) which we hope to help provide even more funds for development, beyond just donations. Also serving a user need (lots of our users ask us to help them get off Gmail).

Lots of interest in how the money is spent - answer: mostly on devs, landed Exchange support recently (big for a lot of MS users), working on Graph support as well, JMAP after that. Updating the calendar (primarily UX/UI there), continuing to improve our Android app, working on a native iOS app and the aforementioned Thundermail service.

We publish yearly reports and will publish one again this year detailing all this.

Here is a 2025 recap: https://blog.thunderbird.net/2025/12/thunderbird-2025-review...

But the blog has a ton of updates across the different efforts: https://blog.thunderbird.net

Happy to answer questions and we are an open source project so feel free to reach out to us and engage if you really want to see how the sausage is made!

*Edit: More context on what Thunderbird Council is*

After reading a bunch of negative comments here, let me add a little on the bright side. I've been using Thunderbird for many years, currently both at home and at work to manage gmail accounts, pop at home, imap in the office. It works great for me, with a few annoyances but nothing serious.

As for the donations, Thunderbird seems to be somehow apart from Mozilla now, so I don't think much about specific org structure and will gladly donate.

Maybe on paper there're dozens of alternatives, but when I consider my specific requirements, I haven't found anything better, YMMV.

Campaigns like this need more info. This page doesn't answer any basic questions.

How much money do you currently get? How much money do you need and how will you use it? Does it even go directly to Thunderbird development or will be used up by Mozilla for other projects?

Edit: I found some info here: https://www.thunderbird.net/en-US/donate/

Still, my point stands that communication around it should be super clear and available on all pages where they collect money. It shouldn't require me to search for it.

I really like Thunderbird, it's the only truly cross-platform mail app, with K9 also now on Android.

Works perfect, I even migrated my Windows install to Linux just by copying the data folder, absolutely seamless.

Not sure why people are hating on it so much here. Point to an alternative with the same features?

I wish Thunderbird fix their plain text editor (it is at level of old Notepad, and chrome for it looks ugly, and line wrapping is a mess, especially with in-line quotation), add ability to store Folder properties (including Identity used for this folder, retention period and such) as IMAP properties and not locally to have same settings on different devices.

And, yes, proper support for Sieve, including per-folder Sieve. Sieve is a pain after they changed something and 3rd party Sieve plugin died (become Electorn Application).

Now Thunderbird has so many rough edges (I named only my top-3, but I'm sure anybody can add others!), but still one and only usable cross-platform e-mail client.

Oh, yes, development pace is unbearable slow: after killing "Manually sort folders" plugin it takes more than year (!) to add this as "core" feature with huge help from aforementioned plugun's author. Very slow process of review, integrating, releasing which takes MONTHS to integrate ready feature. It should be very discouraging for contributors.

Thunderbird now provide like 10% of features of old and almost forgotten (but still alive) windows-only client "The Bat!" from end of 1990s, beginning of 2000s and was written by team of like 5 people.

But still, I've donated!

> We don’t have corporate funding

I thought you were owned by Mozilla? A corporation that has over half a billion dollars in yearly revenue? If they decided to allocate zero funding to you, wouldn't it be vastly more effective to start some sort of campaign/movement (either internal or external) to get that funding back, or to entirely fork and leave Mozilla to be your own independent project, than to ask for random donations?

> MZLA Technologies Corporation is a wholly owned for-profit subsidiary of the Mozilla Foundation and the home of Thunderbird.

I guess I don't understand why the open-source email client with zero revenue potential is managed by a for-profit subsidiary, nor why that for-profit subsidiary is begging for donations.

Shouldn't this whole thing be managed by the non-profit Mozilla Foundation?

I installed Thunderbird for the first time in a couple of decades recently. My impression was that it's very feature rich but also quite ugly and not friendly to new users. It comes with a lot of assumptions about what the user wants to do and how, and I found myself having to use cheats and workarounds from the outset. I wanted to import a batch of disparate .eml files that had been seperately exported, and after 15 minutes I was starting to think it might have been easier to just do it in Python.

I also didn't care for the tabbed panels, which make it feel as if the entire thing was just ported from a browser. It really needs some fresh design and user interface work.

Just donated. Have been using Thunderbird for years. I once donated to Wikipedia - and they have billions I heard - so might as well donate to another important piece of software for my digital life.

Now that I read the comments I find out Mozilla might have enough money and a CEO taking in millions. Any recommendations for a good email client on Linux? Just as a backup for now...

As of late 2024, Thunderbird was doing well financially.[1] About $8 million a year in donations, most spent on developers. What went wrong?

It's basically in maintenance mode. Are they trying to add features nobody really wants to justify their existence, like Mozilla?

[1] https://chipp.in/news/thunderbird-financials-doing-really-we...

I'd be more likely to donate if they kept it like it was 10+ years ago. I still use an old version because they keep making gratuitous changes to the UX.

I seem to remember an article in lwn a year or so ago about them hiring a new PM who was basically a donation campaign manager, and one of the points was "telemetry is good, actually, and should be opt out not opt in."

I get the feeling the amount they fundraise is more a quarterly target than a requirement, but I could be wrong. All of mozilla gives me a bad taste recently.

Mozilla brings in almost $700 million per year, they have more than enough money to sponsor MZLA/Thunderbird development.

To be honest, I wish Thunderbird would become part of LibreOffice, to become a real contender to MS Outlook/MS Office.

Mozilla is managing Thunderbird as a second class citizen since way too long.

Interestingly, I used Thunderbird for years, it was really the best client for some times on Linux. But as the development stalled, I moved to Gnome Evolution, the nice integration with the general Gnome desktop made the switch less painful (at the start, it was hard, Evolution was not that good). But Evolution improved nicely, less bugs, faster, still well integrated into the desktop and I see no reasons to switch back to another tool.

The only change in my workflow is that now, I am also using in parallel a stupid command line tool "vibe coded" in Python to read my emails. It allows me to quickly check my emails out of VS Code in a Claude Code session, a bit like when I was doing my emails directly in Emacs :-)

I really don’t understand the structure that Mozilla has setup here where Thunderbird lives under their for-profit branch, but is so dependent on donations. I remember reading they were considering charging for Thunderbird services when the move was announced 6 years ago, but as far as I can tell, nothing has happened and they’re still desperate for funding.

Now not only does it still need donations, the tax exemption for donors has evaporated. Great.

Wasn't Thunderbird Pro the avenue for extra project financing? Why does it take so long to launch an email service?

I wish I could use Thunderbird at work now that it has Exchange support . Unfortunately we're mandated to use Microsoft Outlook. Outlook feels like it has completely been forgotten by Microsoft. I don't recall the last time they updated anything meaningful in the product (at least on macOS), it's quite a mess of a product. Wishing Thunderbird all the best it's the competition we need.

Donated. I don't even use it, but we needed it for opening email archives from clients at my old employer. We need as many options as possible.

How much money goes into the pocket of the Mozilla CEO? How much is used to actually pay the people and to cover infrastructure costs?

Is there still no way to export and import your filters in Thunderbird? This is why I shunned it 20 years ago. The absurd idea that you're going to manually run around to all your computers all the time and manually set up (and maintain) mail filters should have been rejected in version 1.0.

I recently started using Thunderbird for work which uses O365 (horrific service) for mail. I've found that 2FA with O365 to be totally unreliable no matter the client, even using the iOS app.

Does anyone use Thunderbird with Gmail and 2FA, and does it work correctly 100% of the time there?

How many more donations until we get a functional UI like we used to have, and a system tray icon on Linux?

If you want to donate, I suggest you look at the Betterbird fork: https://www.betterbird.eu/

Long shot, but I'll ask. For a while Thunderbird spam filter will work fine. Then, spontaneously, it stops working and starts showing me many which are obvious, identical junk. And after flagging them as junk, it doesn't seem to learn anything.

For when this happens, it would be nice to have an explicit (and easy) way to blacklist items. Creating new filters for each of them is too involved.

If you press the browser’s back button on the donation page, they send you to a page pestering you for your email address so they can send you a reminder to donate later. Talk about a dark pattern.

Mozilla has really gone off the rails. An organisation who claims to work on behalf of the user and who makes a web browser, actively hijacking the user experience to peddle for a few dollars?

Why the heck is Thunderbird “fully funded by financial contributions from [their] users”? Where do the billions of dollars from Google go? All the stupid doomed side projects which no one asked for nor wants and are abandoned after one year?

Now that Protonmail has an ok-ish PGP interface they've been bleeding users, it's a really important piece of the open source infrastructure and I hope folks support it -- back when I was with Mozilla, I said they should focus on using less ram and less CPU, not weird little side quests like... well the list goes on and on.

One thing I think we should do is allow Thunderbird to return to the early Firefox model -- it's a stable product, that people can install extensions on. Save for security updates and keeping up with OS quirks, it doesn't need constant tinkering.

I'm not saying they don't need the money, I'm just saying I'm concerned how and why we got to this point.

Why mozilla doesn't approach a similar strategy with firefox? I see with thunderbid most of the recent focus is in making the product better and the raising of the funding it's focused on user donations. With Firefox the focus is not in making the product better and instead on adding useless features, and the raising of funding is focused in advertising and random quests not related to the browser

I was about to donate $5 until I saw the minimum is $7 CAD. What?

I've just donated. I use Thunderbird every day and have used it for years now. Mozilla, Firefox and Thunderbird are very important to me and my internet usage. For all the complaints (many just unwarranted in my opinion) I'm a happy user.

The other day I cam to my computer with Thunderbird showing me a full page screen instead of my email list that I had open before. Not going to donate to projects that disrespect users like that - my computer is not your advertising space even if you consider your ads "helpful information".

As a lot of people in this thread advise against Thunderbird, what do you recommend instead (preferably for Windows as I am stuck on that)?

I have donated ... multiple times. I wish there was a way to keep the "Please Donate" from popping up if we have donated within the last N days, weeks, months, etc.

I tried for a long time to work with Thunderbird, but what kept bothering me was that I couldn’t simply define keyboard shortcuts. In the end, I landed on AERC and created my own extreme Vim-style keyboard configuration (the idea is to look at the list of mails like looking at a buffer in vim) for it. I’ve never been this fast when it comes to email.

https://aerc-mail.org/ https://github.com/rafo/aerc-vim

I wish there was a system that lets users put up a donation that is released once a specific bug is fixed or a specific feature is implemented.

Wouldn't that be cool? The company would have a list of tasks with a dollar amount next to it.

I for one have been dabbling with a bug in ThunderBird for days now that drives me mad:

I recently created a folder in Thunderbird and called it "archive". No way would I have expected that this will lead me to a bug and will take hours out of my day: There seems to be no way to get rid of this folder anymore.

Things I have tried:

"Keep message archives in" in "Copies and Folders" is disabled. I tried temporarily enabling it, setting it to some other dir and disabling it again, that did not help.

I have disabled it in "subscribe".

I cannot rename it.

There is no "archive" folder in the web interface of my email provider, so if it Thunderbird somehow created it on the server, there seems to be no way to see, let alone delete it again in the web interface.

I tried deleting archive.msf on disk. That makes the folder disappear after the next start, but it is recreated after about a second.

I deleted folderTree.json and folderCache.json, that did not help.

Torn about this due to multiple factors...but I think the core reasoning remains: if it's a tool you like, there are actual people working on it, and if you want those actual people to stay employed and continue working on the tool, it's in your best interest to do things like donate and talk/share about them.

"If you get value from Thunderbird"

I'm reading this and I'm feeling like, maaan, I wish you hadn't asked me that.

So, compare to Mozilla (which apparently they're not with anymore?) I actively use Firefox and probably more importantly, I remain very impressed with their ability to try to keep up with the times. They do fail at this sometimes, but over 20-30 years, that track record is solid.

Thunderbird? Ugh. I want it to be good, but I'm not so sure there's much of a point here anymore. My line in the sand was different colored multiple accounts which was trivially easy and then one day wasn't; moreover AI is really killing them there for me (in terms of taking something old like Claws or Neomutt and very easily customizing it a way that was too much of a pain before)

I wouldn't mind donating if they separate it from Mozilla and move it to Europe.

Thunderbird will provider their PRO services using stalw.art as email backend. I was considering using it too to replace really old mail system in our company. It looked like modern stack using jmap, but it seems thunderbird actually does not support jmap? Or is it only in their PRO extension? Does it mean I cannot use this unless it is with their services? I'm confused.

Of course there is still IMAP, but I hoped for better.

Is that a Stripe screen? Set up american style to reduce friction, not supporting 3d secure, which means european credit cards will deny by default?

Thunderbird is great <3 use it daily, for all my work and personal mail. Donating

Edit: They won't let me: "We couldn't verify that this email address is able to receive mail. Try again or enter a different email address to continue."

A bit more context would be helpful, as someone happy to donate -- what is the current situation, why the urgency? Just some more info would be good.

I haven't used Thunderbird in 15 years.

Donated anyway. I was very happy with it for the years I did use it.

I have actually bought a lifetime license for em Client.

Thunderbird had consistently (Windows / Linux) a bad performance for me and feature and UX wise it has always only been okay for me.

Still important that a few FOSS solutions for email exist, though.

My usual reminder that actually Mozilla has a lot of money (mostly from Google), and, for example, donates six figure numbers to random political organizations not related to browsers and internet (not EFF)

Here is a breakdown, which was posted on HN few years ago – https://lunduke.locals.com/post/4387539/firefox-money-invest...

Mozilla gets like 500 trillion a year from Google, no, I will not give money.

I used TB happily for years on Mac OS but its font rendering on Linux was one of the main reasons I never switched.

when i used windows i was happy with The Bat email client: https://www.ritlabs.com/en/products/thebat/download.php

I wish I could donate without entering an email address.

There's a bunch of misinformation in the comments here, so I'll just add that I started using Thunderbird again around the time they became independent (ish) of Mozilla and I've really enjoyed it, it's fast, supports all my email accounts and the Android app is good too.

Made an account just to say that I will not support the bloated mess that is Thunderbird that pushes on you a new way to configure it, a new layout and new workflows with every major update, makes it difficult to set up text-only mail and messes up line breaks every so often with no way to properly configure it, which should be developed by Mozilla, which is flush with money but rather spends it on theming their software and executive salaries.

I switched away from Thunderbird about a year ago and couldn't be happier I have made the change.

I'm gonna say it: we need to build a Thunderbird replacement. It's got too much technical debt. It can't convert new users. We need something that does.

In this thread, a bunch of people complaining about an open source app not asking for donations the right way but will be the first people to ask "Why didn't they stick a donate button on the website" or "they should have asked for money!"

What was the source of this link OP? A monthly newsletter?

Either way, they have more information on their donate page as well as a whole knowledge base set of pages:

https://www.thunderbird.net/en-US/donate/#faq

https://give.thunderbird.net/hc/en-us

Anyone using Thunderbird was forced to see this, not sure we (or the well-funded corp) need another round.

Sorry, isn't Thunderbird meant to be "true FOSS" and essentially feature complete?

By donating to MZLA Technologies Corporation? Then I guess I'll switch to KMail or Evolution.

How is their Exchange support going? Flawless support for 365 and a UI that can be made to function like outlook for people to transition over?

Mozilla is such a weird company, asking users to donate and keep one of their projects alive, while dumping billions in useless initiatives is really dishonest.

Yeah, no. They finance a lot of DEI stuff instead of investing it in the code.

Once they are no longer part of Mozilla, I would be happy to consider it.

Enable Usenet support in the Android build...

I miss the days we needed Thunderbird for email...such an innocent time.

I really think Mozilla has run it's course. Just die already so there is room for something new.

I use Thunderbird on both Linux/Android as my sole client for personal email. I'm mostly pretty happy with it, aside from search. My use case is mostly receiving email rather than sending email however. I would be much more amenable to donating if I knew that my donation would be going to support Thunderbird specifically and not rolled up into the parent MZLA Technologies Corporation, but I understand that's usually impractical.

DO NOT donate to Thunderbird. Let it "die". As with all of Mozilla's software, that would be the best outcome - if it does, someone who isn't totally incompetent might fork it and actually improve it.

Literally every change that's been made to thunderbird in the last 10+ years has made it worse. Mozilla are doggedly using the same philosophy as they are with firefox: "in what new and exciting ways can we make it more shit?".

There are a bunch of things that I used to do in thunderbird with no problem on much less powerful machines that I can't do today.

For example, since they decided to rewrite their perfectly-functional calendar parsing in a trash language, it now eats 100% of my CPU for ~30mins at a time trying to parse my decades-long, many-many-thousands-of-entries calendar. Then when it finishes it notices that it's been 30 mins since it synchronised my calendar, so it syncs and starts parsing all over again! This effectively locks up the whole of thunderbird, making it totally unusable. This issue has persisted for years. The solution I came up with is "stop using thunderbird for my calendar".

There's a similar fun bug which means it won't sync my contacts anymore either. A feature that I had by about 2010 which my nokia phone could manage, modern thunderbird cannot do.

If you'd like another 20 examples of how it's worse today than it was 10 years ago, just ask, and I'll write up a hundred thousand words or so of vitriol.

It's extremely likely that next time I upgrade my distro I'll be shopping for a new email client. Currently I have thunderbird marked as held so that it doesn't upgrade. When I upgrade my distro there will be a new version of thunderbird, and I'd estimate about a 90% chance that that's when I'll make my exit, after ~20 years or so.

It's sad. Thunderbird used to be a great piece of software.

Don't give mozilla your money.