
ThunderCast
An inside look at the making of Mozilla Thunderbird, and community-driven conversations with our friends in the open-source software space.
MZLA Technologies Corporation · Alessandro Castellani
Show overview
ThunderCast has been publishing since 2023, and across the 3 years since has built a catalogue of 23 episodes, alongside 1 trailer or bonus episode. That works out to roughly 20 hours of audio in total. Releases follow a roughly quarterly cadence, with the show now in its 3rd season.
Episodes typically run thirty-five to sixty minutes — most land between 53 min and 57 min — and the run-time is fairly consistent across the catalogue. None of the episodes are flagged explicit by the publisher. It is catalogued as a EN-language Technology show.
The show is actively publishing — the most recent episode landed 2 weeks ago, with 2 episodes already out so far this year. The busiest year was 2025, with 15 episodes published. Published by Alessandro Castellani.
From the publisher
An inside look at the making of Mozilla Thunderbird, and community-driven conversations with our friends in the open-source software space.
Latest Episodes
View all 23 episodesThundercast - S3E2 - Contributor journey
S3 Ep 1ThunderCast - S3E1 - Roadmaps
ThunderCast, the official Thunderbird podcast is back for another season! Let's kick things off with some insights on our roadmaps and what's ahead for our desktop and email clients.User testing discussions: https://thunderbird.topicbox.com/Roadmaps: https://roadmaps.thunderbird.net/Developer guides: https://developer.thunderbird.net/Ideas for Thunderbird desktop and mobile: https://connect.mozilla.org/User support for Thunderbird desktop and mobile: https://support.mozilla.org/Submit your questions at [email protected] ★ Support this podcast ★

S2 Ep 15State of the Thunder 14: The 2026 Mobile Roadmap
As 2025 winds down, its time to start thinking of what we want to achieve for our Android AND iOS apps next year. Alessandro walks us through the 2026 mobile roadmap, covering our urgent priorities, feature wish list, and a glimpse at our upcoming design plans for the entire Thunderbird project.Resources: Current Android Roadmap: https://github.com/orgs/thunderbird/projects/19 TB Pro Announcement: https://blog.thunderbird.net/2025/04/thundermail-and-thunderbird-pro-services/ Mobile Development Matrix: https://matrix.to/#/#tb-mobile-dev:mozilla.org Thunderbird for Android GitHub Issues: https://github.com/thunderbird/thunderbird-android/issues ★ Support this podcast ★

S2 Ep 14Bonus Episode: An Android Retrospective
bonusIf you can believe it, Thunderbird for Android has been out for just over a year! In this episode of our Community Office Hours, Heather and Monica check back in with the mobile team after our chat with them back in January. Sr. Software Engineer Wolf Montwé and our new Manager of Mobile Apps, Jon Bott look back at what the growing mobile team has been able to accomplish this last year, what we’re still working on, and what’s up ahead. ★ Support this podcast ★

S2 Ep 13State of the Thunder 13: How the Roadmap Gets Made
Welcome back to another State of the Thunder! In this episode, Managing Director Ryan Sipes is leading us through how the Thunderbird roadmap. Unlike other companies where roadmaps are driven solely by business needs, Thunderbird is working with our community governance and feedback from the wider user community to keep us honest even as we move forward.Resources: Mozilla Manifesto: https://www.mozilla.org/en-US/about/manifesto/ Share big ideas: https://connect.mozilla.org Report desktop bugs: https://bugzilla.mozilla.orgReport Android bugs: https://github.com/thunderbird/thunderbird-android/issues/Engage with the Thunderbird Council: https://council.thunderbird.net Desktop roadmap: https://developer.thunderbird.net/planning/roadmap Mobile roadmap: https://developer.thunderbird.net/planning/roadmap ★ Support this podcast ★

S2 Ep 12State of the Thunder 12: Community, Android, and Mozilla Connect
We're back with our twelfth episode of the State of the Thunder! In this episode, we're talking about community initiatives, filling you in on Android development, and finishing our updates on popular Mozilla Connect requests, including true Conversation View! ★ Support this podcast ★

S2 Ep 11State of the Thunder 11: Mozilla Connect Updates
State of the Thunder is back after a short hiatus for a new season of answering questions and providing our community with updates on all our products, from mobile and desktop clients to the upcoming Thunderbird Pro! In our first episode of the new season, Alessandro and new cohost Michael Ellis tackle a new batch of your questions with help from members of the Thunderbird team and community. Then they provide updates on the 20-ish top Thunderbird suggestions in Mozilla Connect. ★ Support this podcast ★

S2 Ep 10State of the Thunder 10: Answering Community Questions!
Welcome back to State of the Thunder! In this edition, we're taking more community questions on a range of topics. From improving Settings to the role of Add-ons and more, the Thunderbird team is tackling your most urgent inquiries! ★ Support this podcast ★

S2 Ep 9State of the Thunder 9: Answering Your Thunderbird Pro Questions
In the latest State of the Thunder, we're answering your questions about the upcoming Thunderbird Pro offerings and introducing our new head of Community Programs. Michael Ellis is here to help us better serve our community, and he's placed a call for ideas on Mozilla Connect for ideas to improve the Thunderbird community: https://connect.mozilla.org/t5/discussions/have-ideas-to-improve-the-thunderbird-community/m-p/100264#M38972 Question 1: With these new services, will there be less effort spent on desktop and mobile? Answer: No! Lately we've added several new developers to our desktop and mobile teams. TB Pro is a collecting of projects (not products) that mean to coexist besides our core products and fill in missing pieces for users. Question 2: Why is Appointment being developed as a stand-alone? Answer: As a stand-alone, users can adapt it for their individual use, and core users don't have to use it if they don't want to. Also, this gives us time to help the underlying protocols add support for what Appointment needs to run natively. Question 3: Can you deploy Appointment on your own infrastructure? Answer: Yes! We know many of our users like to self-host and so we wanted this option. But offering to manage it on our own infrastructure is not only good for people who don't want to manage it themselves, but it's an opportunity to not only keep Thunderbird financially sustainable but to raise the resources to make it truly competitive. Question 4: Are there plans to make Send part of the core Thunderbird app? Answer: No, not for the foreseeable future. We'd like to have it as an opt-in system add-on. We still have Filelink, which has allowed us to build Send. Developing Send can possibly allow us to expand on Filelink's abilities! Question 5: In Send, is there a file size limit for each file? Answer: As far as we know, no. You'll have a limit of how much storage you'll have, which right now we're imagining will be 500GB for a normal subscription. Subscription costs will both pay for the storage itself and its management. As Send is open source, we'll have free options for folks who want to self host with their own storage. Question 6: Will I be able to use Thundermail with another client? Answer: Of course! As you can imagine, we're big fans of open standards! Thundermail will also support JMAP. Question 7: Any plans for future Google-like products connected to Thundermail? Answer: This is largely up to the community! We have no shortage of ideas how we could expand TB Pro into those spaces, but this depends on our success. (So be sure to sign up for the mailing list and use the service if you us to move closer to a fully featured suite.) For some of those services, stakes are very high, so before moving into them we'd want to be certain we could do them well. Question 8: Do we have a public roadmap for these projects? Answer: We've started a process to make a public roadmap, along the lines of our mobile roadmap which shows current and planned sprints. This will be done in collaboration with the Thunderbird Council and will help our community get involved with these projects. Resources: Call for ideas to improve the community: https://connect.mozilla.org/t5/discussions/have-ideas-to-improve-the-thunderbird-community/m-p/100264#M38972 Consensus scheduling proposed standard: https://datatracker.ietf.org/doc/draft-ietf-calext-vpoll/ Filelink info: https://support.mozilla.org/kb/filelink-large-attachments TopicBox Mailing Lists: https://thunderbird.topicbox.com/latest Thunderbird GitHub Repositories: https://github.com/thunderbird Bugzilla: https://bugzilla.mozilla.org/ Thunderbird Development Docs: https://developer.thunderbird.net/ ★ Support this podcast ★

S2 Ep 8State of the Thunder 8: Eating Frogs, Roadmap Progress, and Fundraising
Welcome back to the latest State of the Thunder! In this recording, we're eating frogs (metaphorically) and checking in on our roadmap progress, sharing our tips and tricks for Thunderbird development tools, and talking about the hows and whys of our fundraising campaigns. ★ Support this podcast ★

S2 Ep 7State of the Thunder 7: Extended Support Release 140 (and explaining our four channels)
In this latest State of the Thunder, we're discussing the upcoming yearly ESR, 140.0, which is due out June 24, 2025. We explain our numbering convention and our different channels, which comes from Firefox, and the difference between ESR, Release, Beta, and Daily. Find out why we're encouraging to use the monthly Release channel, but how this won't take anything away from ESR. Learn more about what channel is right for you (especially if you use add-ons), how to help us with using Beta and Daily, and how to safely move between ESR and Release. And as always, we finish with a community shoutout! Resources: What Train is It Now: http://whattrainisitnow.comMonthly Release Channel Blog Post: https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/Choosing a Release Channel: https://support.mozilla.org/kb/choosing-thunderbird-release-channelTesting Beta Support Article: https://support.mozilla.org/kb/thunderbird-betaTesting Daily Support Article: https://support.mozilla.org/kb/thunderbird-dailyRelease Channel Support Article (with info on safely downgrading): https://support.mozilla.org/kb/thunderbird-releaseAdd-on Compatibility Add-on: https://addons.thunderbird.net/thunderbird/addon/addon-compatibility-check/tilorenz's Calendar grid patch: https://phabricator.services.mozilla.com/D251992 ★ Support this podcast ★

S2 Ep 6State of the Thunder 6: Release on Snap and flatpak, Accessibility, Mozilla, and building Thunderbird
We're back with another State of the Thunder! In Volume 6, we're discussing the complexities bringing the monthly Release channel to snap and flatpak, increasing accessibility for assistive technologies, our relationship with Mozilla, why building Thunderbird is hard (and how we're trying to make it less so), and more! ★ Support this podcast ★

S2 Ep 5State of the Thunder 5: Setting Roadmap Priorities
In the fifth volume of State of the Thunder, we're focusing on priorities. How do we begin on a priority roadmap project? How do we decide what to release and when to release it? And how do we adjust priorities for the benefit of our users? Additionally, we have news about Thunderbird Sync (!), what MZLA is doing to improve the open ecosystem, and updates on Thunderbird Pro and the mobile apps. ★ Support this podcast ★

S2 Ep 4State of the Thunder 4: 2025 Roadmap Priorities
Previously on State of the Thunder, we talked about how we created our desktop roadmap for 2025 and 2026. In this installment, we're diving into how we prioritize work on the desktop app and how we're trying to get better at completing our high-priority items. If you've ever wondered, "When is that feature going to land?" this State of the Thunder is worth listening to! ★ Support this podcast ★

S2 Ep 3State of the Thunder 3: Our Mobile Roadmap (Android AND iOS!)
In the latest State of the Thunder, we're talking all about our mobile apps, currently on Android and coming soon to mobile. Sr. Manager of Mobile Engineering Philipp Kewisch leads the discussion on the the roadmap, responding to frequently requested features, and our predictions for the iOS Alpha. ★ Support this podcast ★

S2 Ep 2State of the Thunder 2: Bugzilla backlog, stability, and collaborating with the Council
In our second State of the Thunder, we expand on the purpose of these meetings and go back to our roadmap. From there, we talk about bugs and stability, discussing how to tackle the backlogs of bugs in Bugzilla and whether Thunderbird is more or less stable now than in years past.We also chat about how to improve collaboration between MZLA and the Thunderbird Council, and finish with technical discussion on the address book's SQLite database and the Thunderbird CLI. ★ Support this podcast ★

S2 Ep 1State of the Thunder 1: Working in the open on the 2025 roadmap
In our inaugural State of the Thunder, Alessandro Castellani, Director of Desktop and Mobile apps, leads a discussion on the 2025 desktop roadmap with members of the Thunderbird team and Council. Beyond features, the chat covers our users, our values, and our commitment to working in the open. ★ Support this podcast ★

S1 Ep 6ThunderCast #6: Office Hours Q&A
The Thunderbird team has resumed our monthly Community Office Hours sessions, and the most recent was an open forum Q&A that focused largely on K-9 Mail and Thunderbird for Android. We also answered some of your questions about Thunderbird for Desktop, including Exchange support (it's coming)! Here's a lightly edited version of that session for you to listen to. If you have questions for us to answer in a future Office Hours sessions, just send an email to [email protected]. 00:00 Intro02:00 Exchange Support for Android?03:22 Add-ons For Android? 06:30 Upgrade Path From K-9 Mail?12:06 Android: CalDAV and CardDAV?16:11 Mozilla Sync & Thunderbird for Android?22:06 Exchange Support on Desktop?24:35 Proper Threaded & Conversations View?30:55 Full Sender Name Column?33:03 What About Thunderbird Webmail? ★ Support this podcast ★

S1 Ep 5ThunderCast #5: Remote Work 101
The Thunderbird team is a remote-first, globally distributed group, so it made perfect sense to devote an episode to Remote Work! Join Heather, Chris, and Jason for some useful tips and tricks to make your daily remote work more enjoyable and more productive. We also include tips from ThunderCast listeners Pedro and Mike, who emailed us at [email protected]. (You can do the same if something's on your mind.)Plus: An inside look at the upcoming Thunderbird Send service, some fascinating origin stories, and geeky Raspberry Pi solutions for weather and BBQ. Software & Articles We Mentioned:Cherrytreedraw.ioSynergyThe Pomodoro TechniqueWorking on Distributed Teams at MozillaContribute To Thunderbird Without Knowing How To Code(00:00) - Intro (01:05) - Meet Heather (02:10) - Heather’s Origin Story (04:40) - Your notes can help everyone! (06:38) - Meet Chris (07:37) - Chris’s Origin Story (11:30) - Geeking out (20:45) - Thunderbird 115 Updates & Flatpak (22:04) - Thunderbird Send explainer (31:48) - Remote Work Tips & Tricks (51:44) - Community Voice: Tip from Pedro (55:53) - Community Voice: Tip from Mike (58:32) - Outro ★ Support this podcast ★

S1 Ep 4ThunderCast #4: Will The Real moz://a Please Stand Up?
The Thunderbird team is back from the Mozilla All-Hands event, and we're overwhelmed in the most positive way. In addition to the happy vibes we're all feeling from meeting most of our colleagues in person for the first time, we have a lot of takeaways to share. in this episode Ryan, Jason, and Alex talk about how Mozilla is building AI tools for the good of humanity, and how our perception of AI has changed dramatically. Plus, the problem with the "hey Mozilla, just build a browser" argument. Episode #4 is light on actual Thunderbird talk, and more focused on Mozilla as an organization, the current state of the internet, and the future of AI. We hope you enjoy it as much as we enjoyed discussing it! Have a question or comment for us? Just email [email protected]! (00:00) - Intro (00:28) - The All-Hands Hangover (03:10) - The Thunderbird Team IRL! (09:42) - moz://a beyond the products (13:36) - Tackling AI & web issues (19:24) - The "just build a browser" argument (21:46) - Alex changes his mind about AI (23:38) - Building AI tools for good (33:09) - Fighting for the soul of the internet (40:11) - Thunderbird and AI? (47:16) - Warm fuzzy feelings (52:51) - Outro ★ Support this podcast ★