Lessons from the death and rebirth of Thunderbird

Ryan Sipes told the audience during his keynote at GUADEC 2024 in Denver, Colorado that the Thunderbird mail client "probably shouldn't still be alive". Thunderbird, however, is not only alive—it is arguably in better shape than ever before. According to Sipes, the project's turnaround is a result of governance, storytelling, and learning to be comfortable asking users for money. He would also like it quite a bit if Linux distributions stopped turning off telemetry.

Sipes is managing director of product for MZLA Technologies Corporation, the subsidiary of the Mozilla Foundation that allows Thunderbird to take donations and so forth. When Sipes joined the Thunderbird project on a part-time contract as community manager in December 2017, one of the most common questions he was asked was "isn't Thunderbird dead?" That wasn't, he said, an unreasonable question.

He joined five years after a TechCrunch article declared the death of Thunderbird. The author declared it dead because the Mozilla Foundation had announced that it was pulling resources from the project and putting it into maintenance mode. In 2016, Mozilla started looking to spin off the project. In May 2017 the Thunderbird project announced it was allowed to stay under the foundation as its fiscal and legal host but on the condition that Thunderbird operate independently. It's little wonder that many people thought that Thunderbird was dead.

Thunderbird was not dead, but it was not particularly healthy, either. Sipes said that, when he joined, Thunderbird was frequently in an unbuildable state. "We had what we called red-tree days where upstream (Firefox) broke us", and those "days" would actually mean weeks or months where the project wouldn't build.

But Sipes saw potential. Prior to taking the Thunderbird community manager role, he had worked for System76, a vendor that sells Linux laptops, desktops, and servers. He said that companies that were planning to deploy Linux across the organization or for their developer groups would often ask him what would serve as a one-to-one replacement for Outlook. He would recommend Thunderbird as the closest replacement, even though it was not a perfect fit. When the Mozilla job opened up, he said, "I thought I was super-hot stuff, I'll go over there and I'll fix this up". Seven years later, he's still at it—albeit in a permanent role in product management.

Sipes credited the Thunderbird Council (the project's elected governing body) for re-energizing the project by setting up open project governance, and ensuring that there were decision-makers with ownership to say where efforts should be focused. Governance, he said, was crucial to turning the project around. But that doesn't mean that it was painless. "Good governance, even the best governance, is never pretty":

I have yet to be in a community that works but doesn't have sparks flying every day, real debate happening. And I will say that if you look back on Thunderbird's mailing list at this time, it's not pretty, constant arguments, competing visions for the future. But what I'm telling you is you have to have that in an open-source community for things to actually move forward. If you don't, then the project is probably stagnating.

The project was no longer stagnating, but its revenue certainly was. Sipes said that Thunderbird's revenue "was on track that year to be $500,000", even though it had approximately ten million daily active users (DAUs). He recounted seeing an article that said that Slack also had about ten million DAUs, but its revenue was at one to two billion dollars at the time. What he saw happening at the time pointed toward the death of Thunderbird; it "is going to slowly just disappear". He wondered why Thunderbird could not be sustainable. There was no good answer, he said, so he kept asking.

Money (that's what I want)

The solution turned out to be simple, Sipes said. But first the project tried "all these super-complicated ways" to make money that did not work. Finally, he said, he asked "what if they [users] don't know that Thunderbird is going to die, and what if we just slap it like right in their face" and ask for money. Initially, he received a lot of pushback on the idea. People in the project didn't feel comfortable asking for money, "they said it's spammy, it's tacky". Sipes said that he eventually realized he was having the wrong conversation. So, instead, he started asking instead "which is more cool, we ask for money twice a year, or Thunderbird goes away forever?" Framed that way, he started getting somewhere.

So the project started running donation campaigns twice a year by using a dialog within Thunderbird that users would have to acknowledge one way or another. This did not, it turns out, offend its users. Far from it. Sipes said that he asked users what they thought of the appeal, and they would respond "what appeal?" People are so accustomed to seeing ads, promotions, and upsells in applications that it "did not trigger at all in their psyche". Either they gave or closed the appeal, and that was simply a two-second transaction in their day.

So this stuff is not as annoying as you think. We are coming off doing four appeals over the last 12 months. Four full-screen appeals. Still many of the users I ask say I honestly have never seen what you're talking about. So far we have not hit any kind of fatigue around the in-app appeals.

The appeals have been effective. The first year that Sipes was with the project, it wound up bringing in about $700,000 in revenue. The past year, he said, it has brought in $9.1 million. Its efforts haven't been limited to in-application requests, though. A blog post about Thunderbird's 2022 financial report published last May notes that the project also increased its work to communicate with users and explain how it uses money it receives in donations.

This bird has flown

Moving on from fundraising, Sipes discussed the problem of changing the perception that Thunderbird was dead. One thing that open-source projects are bad at, he said, is owning their image and brand. The participants in open-source projects are usually developers first, "so it's not an innate skill that a lot of folks possess in this space to tell a story" about the project or software that they are building.

One part of telling Thunderbird's story was to modernize the project's branding and add some excitement to its release announcements. The old logo, Sipes observed, looked like a wig on top of an envelope "and once you see it, you can't unsee it. This is not the future, this is not even today". His push for a new logo met the usual resistance, "everyone was telling me, don't do this [...] people will be confused with something new". Sipes said that users' familiarity with the old logo was a problem, not a positive. Even if Thunderbird changed everything, he said, users would still see the old logo and think that nothing had changed. "So fundamentally, we had to tell them 'no, you don't know what this is, you've never seen this bird'." Last year, the logo received an overhaul by the original logo's creator, Jon Hicks.

Another thing the project did to draw attention was to give the next release after the new logo a "fancy cool name". The Thunderbird 115 release was called Supernova, though there was no particular reason for the name choice. "I just thought this sounds cool, and people will want to know more."

More importantly, of course, the project did more than rebranding and coming up with release names. Sipes said that the project decided to "destroy expectations" and modernize the user interface. "Not without purpose, like we didn't change it arbitrarily" but to create an experience that matches expectations for what a user interface is like in 2023.

Telling a new story, Sipes said, worked. He showed a slide that showed the trend line for Thunderbird's DAUs that showed steady decline, but then ticking up substantially after the Supernova release.

Lessons learned

Sipes moved on from rebranding to talking about the lessons he'd learned from his time with Thunderbird that could be applied to other open-source projects.

The first lesson, he said, is that a successful project is not just about the code. Users make decisions about software that have nothing to do with the quality of the code, the language it is written in, or "the cool thing that you manage to do that no one else does on the planet." Understanding that is an important step in making other decisions to help drive a project to success.

Another lesson is that governance matters. Sipes said that no matter what happened to Thunderbird's revenue or its legal entity MZLA Technologies, the project would likely continue to exist: "Because we have a governance structure for the project that is independent of everything else." That structure, he said, was crucial for the longevity of open-source software when maintainers come and go. "We have maintainers all the time who have kids and then we have to find a new maintainer for the thing they maintained."

Even though Sipes noted that Thunderbird could exist without revenue, he wanted to make it clear that money was important. "I don't know who in this room needs to hear this, but somebody in this room needs to hear this: money is not necessarily bad." There are some "big hairy projects" in open-source, he said, that it's extremely difficult to get people to tackle as volunteers:

No one has ever, in the history of Thunderbird, updated the IMAP code for free. It has never happened. No protocol code has been updated, to my knowledge, by someone who is volunteering. [...] It's like 600 pages of RFC's! Who wants to do that? It is not like I'm going to get my whiskey, I'm going to sit in my chair, and I'm going to read through the RFC's tonight.

Even faced with that reality, Sipes said that it was eye-opening how much pushback he received trying to get money to move the project forward. That is a mistake that open-source projects should avoid. The vendors that make the software that open source is competing against, he said, "don't hold our values" and they have a lot of resources to promote software that embodies "in some cases, the antithesis of our values". If projects are not willing to use a tool in the toolbox, like money, to compete "then it is our destiny to get left behind forever".

The last lesson, he said, "is own your story". While some people were saying that Thunderbird was dead, "no one tried to tell another story" until 2017. Now, the story he wanted the audience to remember was that "we're here, we're alive, we are the open-source email client that's taking on Outlook, that's taking on Gmail" to show users that there is a better way to manage their email. The project wanted to help users accomplish what they want to do "with the least friction, and the least moral compromise possible".

GNOME, he said, should be telling the story that it is the "next-generation desktop". There has been a trend since the inception of GNOME where "we roll out a feature on the desktop, and we're like this is cool, and then eight years later Mac or Windows adds it to their operating system, their desktop experience". What you see in GNOME today, is what's going to be in other OSes in the future.

Questions

With that, Sipes opened the floor to questions. One attendee said that they were impressed by the revenue numbers; they wanted to know if there were any breakdowns by platform that could show whether Linux users were more generous than those on other platforms. The short answer was "yes", Linux users do tend to donate more per user than those on other platforms. The longer answer was an impassioned plea for Linux distributions to stop removing telemetry from Thunderbird:

We don't know whether we have two million Linux users or 500,000. Please turn telemetry back on. Let the user opt out if they want to. Guys we do not collect any PII [personally identifiable information], we need to know how many Linux users there are so we can make decisions about whether or not to solve problems for Linux users over existing problems on other platforms where we do collect telemetry. I believe that there are probably more Linux users on Thunderbird than on macOS, but the telemetry does not currently say that, and so we make decisions based on the platforms we can see.

Another attendee noted that it was "particularly difficult" to get Linux users to agree to provide metrics and telemetry. Sipes said that this was a good example of owning the story. Everyone here who cares about making good open-source software, he said, has to actively start telling the story that telemetry is needed. "We need to get past this as a community, it's like the money thing, it's another thing that we fight with one arm behind our back" because there are no metrics to understand users to help the projects make good decisions.

No matter how much Thunderbird improves, many users simply prefer using a webmail client that they do not have to install or maintain on their own desktop. I asked Sipes whether the project was ever going to offer webmail. He said that, if Thunderbird continued to draw in more users, he imagined that a webmail experience would happen. The project was already moving onto each mobile platform, Android with K-9 Mail, and an iOS version that would be starting this year, he said. "I think web is the last one we need to create a presence on" to be able to say that Thunderbird has a solution for users no matter what platform they are on. But there was no specific timeline for that to happen.

[Thanks to the Linux Foundation, LWN's travel sponsor, for supporting our travel to this event.]