Thunderbird

We've got some new faces on our growing support team! in this Community Office Hours, Heather and Monica talk to the team about the work they're doing to not only get ready for Thundermail, but improve the support experience for donors, the wider Thunderbird community, and our incredible support contributors.

Resources for Suggesting Features: Thunderbird on Desktop and Mobile - https://connect.mozilla.org/ Thundermail and Thunderbird Pro - https://ideas.tb.pro/

Resources for Becoming a Community Support Contributor: Join the Support Crew Matrix Channel - https://matrix.to/#/#tb-support-crew:mozilla.org Learn How to Write Support Articles - https://blog.thunderbird.net/2024/07/video-learn-about-thunderbird-support-articles-and-how-to-contribute/ Learn How to Help Support Forum Users - https://blog.thunderbird.net/2024/08/video-how-to-answer-thunderbird-questions-on-mozilla-support/ Provide Feedback on Desktop Support Articles - https://github.com/thunderbird/knowledgebase-issues/issues Provide Feedback on Android Support Articles - https://github.com/thunderbird/android-knowledgebase-issues/issues Already a SUMO Contributor? Join the Contributor Discussion Forum - https://support.mozilla.org/forums/contributors/

Resources for Getting Help with Thunderbird: Thunderbird for Android Support Channel (Matrix) - https://matrix.to/#/#tb-android:mozilla.org Thunderbird Desktop Support Channel (Matrix) - https://matrix.to/#/#thunderbird:mozilla.org

In the February meeting, the Bolt Design System Committee aligns on initial setup and ownership for the Bolt Design System repo, began defining cross-platform icon naming conventions, plus works towards component exposure in the documentation site.

Have any questions or want to join the conversation? Come find us in our Matrix room (https://matrix.to/#/#bolt-design-system:mozilla.org). New to Matrix? Find a Quick Start guide here: https://matrixdocs.github.io/docs/getting-started/quick-start

Our Accessibility Standards and Committee Meetings are now recorded and online!

In the February Accessibility Standards & Compliance meeting, the committee advances a draft Thunderbird accessibility statement for review at the next meeting and starts crafting Thunderbird’s accessibility guidelines. The group identifies work needed to extend guidance into the Bolt design system with a lightweight a11y definition of done for design, and development. Finally, the committee discusses adding automated accessibility checks across platforms (including a minimum “accessibility gate”), reviews proposed success metrics, and closes with an open forum for community questions.

In their first meeting, the Design System Governance Committee, composed of MZLA employees and community members, first reviews the 2026 design roadmap. Then they take a deeper dive into tokens, their role in tying together Thunderbird's many platforms, W3 token standards, and how to document them. This work will make it easier for new design team members and contributors to jump into their work, while providing a more coherent experience from desktop to mobile and beyond.

Welcome to the last Community Office Hours of 2025! In this edition, Heather and Monica welcome Sr. Software Engineer Brendan Abolivier and Software Engineer Eleanor Dichary from the Desktop Team. We’re discussing the recent Exchange Web Support for email that just landed in Thunderbird Monthly Release 145. Learn how the team landed this feature and discover future plans for Calendar and Contact support, as well as Graph API

Chapters: 00:00 Intro 03:50 What is Microsoft Exchange 05:07 Why it took so long to add Exchange 14:33 Exchange in Thunderbird 145 18:20 Config options and authorization 27:10 Attachments and storage 32:30 Sync and folder operations 36:10 Filters and notification 39:10 Search 40:20 Feedback and bug reporting 43:00 Mobile and Graph API 49:09 JMAP and future protocols 55:50 Calendar and address book 59:57 Roadmap and EWS deprecation 62:23 Closing

Resources Exchange Mozilla Support Article: https://support.mozilla.org/en-US/kb/thunderbird-and-exchange Exchange Mozilla Wiki Post (with call for testing): https://wiki.mozilla.org/Thunderbird%3AExchange Reach out on Matrix: https://matrix.to/#/#thunderbird:mozilla.org Bugzilla (use Exchange component for reporting): https://bugzilla.mozilla.org/enter_bug.cgi?product=MailNews+Core

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.

Chapters

00:00 Intro 01:47 Thunderbird Pro in Mobile 05:49 How we build a roadmap 07:40 Android initiatives 12:51 Material 3 or Material You 21:05 Calendar Exploration Questions 31:26 Roadmap items for our community 33:34 iOS initiatives

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

If 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.

Chapters:

00:00 Intro 00:54 One Year Retrospective: What Worked & What Didn't 02:47 Closing the Gap with the Desktop Experience 04:00 Synchronization, Old UI & Dark Mode Challenges 05:57 The Difficulty of Rewriting Core Code 08:31 Why Move to a Monthly Release Cycle? 11:11 The "Carpaccio Method" for Development 13:27 The Struggle with "Technical Debt" 17:14 How a Lack of Documentation Slows Down Fixes 20:00 Lessons from Android for the New iOS App 23:41 Developers' Wishlist: A Modern UI & Smarter Features 26:40 Developers' Wishlist: Better Search & Sync 27:50 The Secret Buried Feature: A Powerful Search Engine 30:12 How K9 Users Differ from Thunderbird Users 33:34 How Many People Use Thunderbird for Android? 36:10 How New Team Changes Have Impacted the Workflow 38:29 Community Contributor Shout-outs 43:06 Balancing an Old App (Android) vs. a New App (iOS) 47:02 Who Replies to App Store Reviews? (A Community Effort) 52:44 The Roadmap for Next Year (Android & iOS) 55:03 Wrap-up & Thanks

Welcome back to another State of the Thunder! In this episode, 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.

Chapters

00:00 Intro 00:19 How a software roadmap gets made 02:27 A brief history of Thunderbird 06:24 Writing next year's roadmap 12:16 Community contributions in the roadmap 24:43 Engage with the project 27:56 How we incorporate feedback 29:24 Why telemetry is important 33:12 How people can see our roadmaps

Resources: Mozilla Manifesto: https://www.mozilla.org/en-US/about/manifesto/ Share big ideas: https://connect.mozilla.org/ Report desktop bugs: https://bugzilla.mozilla.org/ Report 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://github.com/orgs/thunderbird/projects/19

In this month's office hours, we're talking with members of our desktop team about finally taking solid steps towards a genuine Conversation View. From backend database updates to in-person design collaborations, get the first look at this long-awaited addition to the Thunderbird desktop app!

No time to watch? Read the blog to get the highlights! https://blog.thunderbird.net/2025/10/video-conversation-view/

Chapters: 00:00 Intro 02:17 What Is Conversation View? 04:14 Why Thunderbird Hasn’t Had Conversation View 05:43 Early Attempts & Global Database Challenges 07:32 Current Limitations of Global Indexing 09:13 The Panorama Initiative Explained 11:01 Building the New SQLite Database 13:36 Work Week in Vancouver: Goals & Struggles 17:10 Technical & Design Challenges 23:22 Design Prototypes & UI Concepts 23:49 The Road Ahead 27:04 Balancing Features & User Experience 27:44 Difference Between Threaded View & Conversation View 29:35 Sorting Options in Conversation View 30:21 New Features Enabled by Panorama 32:41 Calendar Invites & Future Improvements 33:57 Preventing Data Corruption in New Database 36:45 Limitations & Risks of a Single Database File 39:17 Thunderbird Sustainability & Developer Access 41:44 Folder Compaction with the New Model 43:02 Communicating Progress to the Community 46:42 Managing User Expectations 49:15 Value of Work Weeks & Collaboration 52:47 How to Stay Updated (Mailing Lists, Bugzilla, State of the Thunder) 55:23 Future Updates & Community Involvement 56:02 Wrapping Up

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!

No time to watch? Read the summary on our blog here: https://blog.thunderbird.net/2025/09/state-of-the-thunder-12-community-android-and-mozilla-connect/

Chapters

00:00 Intro 01:21 Austin RiverHacks 05:40 Ask-a-Fox 15:13 More Mozilla Connect Updates 16:03 Native system notification integration 24:10 Conversation View 26:51 The new Panorama database initiative 36:04 A few Thunderbird Pro 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.

Chapters:

00:00 Introduction 03:23 Accidental Message Order Sorting 08:49 Move Focus Keyboard Shortcut 11:33 Option for Simplified Thunderbird? 21:16 Thunderbird Version in Ubuntu PPA 24:12 Top 20-ish features requested in Mozilla Connect

In our latest Community Office Hours, we're talking with members of our design team on a recent accessibility (a11y) study. See how Thunderbird performed with screen readers and magnification, alternative navigation, and general cognitive accessibility, and where we look to improve in the future. Find out how to get involved and where to join us!

Chapters: 00:00 Introduction 01:14 The Thunderbird Accessibility Study 02:09 Study Methodology 03:34 Participants and Assistive Technology 05:22 Results and Accessibility Scores 06:32 Screen Reader Findings and Issues 12:57 Cognitive Accessibility Challenges 15:33 Voice Control Findings 17:15 Magnification Software Insights 20:25 Eye Tracking Discoveries 21:55 Conclusions & How the Community Can Help 25:15 Q&A Session with the Team 35:53 Roadmap Impact & Mozilla Collaboration 42:30 Biggest Surprises & Lessons Learned 46:00 Quick Wins & Potential Improvements 47:50 Long-Term Accessibility Strategy for Thunderbird 50:19 Mindset Shift: Accessibility Helps Everyone 51:47 Next Steps: Training, Bug Triaging & Future Studies 55:04 How the Community Can Contribute

Resources: Bugzilla Disability Access bugs and enhancement requests: https://mzl.la/41jrnuv Fable: https://makeitfable.com/ Thunderbird A11y Matrix channel: https://matrix.to/#/#tb-a11y:mozilla.org Thunderbird User Experience Mailing List: https://thunderbird.topicbox.com/groups/ux Thunderbird suggested tools and resources for Accessibility: https://bolt.thunderbird.net/8b179dbfd/p/33ddcb-accessibility Config 2024: Pitching accessible design like a pro: https://www.youtube.com/watch?v=NoHIDWF0d6I

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!

Want the tl;dr of the video? Be sure to check out our blog post at https://blog.thunderbird.net/2025/07/state-of-the-thunder-answering-community-questions/. Want to listen to State of the Thunder as a podcast? Go to https://thundercast.transistor.fm/

Chapters:

00:00 Intro 01:56 Supporting and Sustaining FOSS Projects We Use 05:49 Future UI Settings Plans 14:05 Account Setup and Manual Configuration 21:34 Balancing Complexity and Simplicity 32:58 Benefits of the New Monthly Release Channel 38:01 JMAP Support in Thunderbird 41:12 Maintaining Backups in Thunderbird

Resources: Mozilla Connect discussion on how to improve the Thunderbird community: https://connect.mozilla.org/t5/discussions/have-ideas-to-improve-the-thunderbird-community/m-p/101438#M39415 Stalwart: https://stalw.art/ Thunderbird UX Mailing List: https://thunderbird.topicbox.com/groups/ux Thunderbird Add-ons: https://addons.thunderbird.net/ Thunderbird on Matrix: https://matrix.to/#/#thunderbird:mozilla.org Thunderbird Developers Mailing List: https://thunderbird.topicbox.com/groups/developers Thunderbird Planning Mailing List: https://thunderbird.topicbox.com/groups/planning xkcd "Standards" comic: https://xkcd.com/927

Are you a Linux user who wants to build Thunderbird? Here's a tutorial on how to setup a development environment in Ubuntu, in just a few commands! This is helpful if you're interested in fixing bugs, trying out patches, or making any local changes to Thunderbird.

Tutorial Commands:

Setup tools needed to build Thunderbird $ sudo apt install python3-pip mercurial

Checkout the source code $ mkdir tb-build && cd tb-build $ hg clone https://hg.mozilla.org/mozilla-central source $ cd source/ $ hg clone https://hg.mozilla.org/comm-central comm

Run the bootstrap command from the source directory. Choose 2 (to build Firefox for Desktop). Choose all of the default options. $ ./mach bootstrap

Create your mozconfig file in the source directory with the following info $ vim mozconfig ac_add_options --enable-project=comm/mail

Build Thunderbird! $ ./mach build

Run what you just built! $ ./mach run

We're back with another Community Office Hours, and this month is all about our recent Extended Support Release, 140.0 ESR, code named "Eclipse!" But first, we're introducing a key new member of the Thunderbird team, Manager of Community Programs Michael Ellis! Afterwards, Toby Pilling, Sr. Manager of Desktop Engineering, introduces this ESR's focus on stability, and provide a refresher on the difference between the year ESR and the new default monthly Release channel. We discuss what's in, from Dark Message Mode to Experimental Exchange Support, as well as what didn't make the cut. (Yes, there's an update on Sync!) Finally, we end with how to get new features and fixes every month in the monthly Release.

So put on your ISO-approved shades and learn more about the newest Thunderbird!

Chapters:

00:00 Introduction and welcoming our new Community Programs manager 01:40 What is ESR and why it matters 02:49 Monthly Release vs. ESR 04:50 Stability Focus for ESR 140 05:55 Calendar and database backend plans 07:03 ESR testing and QA 08:20 Getting involved in design feedback 09:03 How the monthly Release improves ESR 12:00 What's In: Dark Message Mode 14:42 What's In: Appearance Settings 19:33 What's In: Manual Folder Sorting 21:15 What's In: Account Hub 27:59 What's In: Native Notifications 33:49 What's In: Experimental Exchange Support 39:06 What's In: Export to Thunderbird Android 40:10 What's In: Table View - Horizontal Scroll Support 41:14 Where to download 140.0 ESR 42:49 What's Out: Full Exchange Support 43:31 What's Out: New Calendar UI and Expanded Account Hub 45:14 What's Out: Sync Update 47:13 Why you should use monthly Release (and where to get it) 49:05 Final thoughts and thank you

Resources: Thunderbird UX Mailing List: https://thunderbird.topicbox.com/groups/ux Interested in the Thunderbird Accessibility Committee? Email laurel@thunderbird.net Suggest new features: https://connect.mozilla.org/ Account Hub Office Hours blog: https://blog.thunderbird.net/2025/04/video-the-new-account-hub/ Manual Folder Sort Bug (and Community Development): https://bugzilla.mozilla.org/show_bug.cgi?id=1846550 Exchange Support Wiki: https://wiki.mozilla.org/Thunderbird:Exchange Get Involved With Exchange: email heather@thunderbird.net Thunderbird + Rust Office Hours Playlist: https://www.youtube.com/playlist?list=PLMY3ZzVsXXyqN6yL9Snm6W19WhBPntj1Z QR Code Import Knowledge Base Article: https://support.mozilla.org/kb/thunderbird-android-import Release Channel Blog: https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/

Have a Macbook and want to build Thunderbird? Here is how to setup that development environment in just a few commands! This is useful if you are interesting in fixing bugs, trying out patches, or making any local changes to Thunderbird.

Tutorial commands:

Install homebrew and tools needed to build Thunderbird $ /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" $ brew install python pipx mercurial $ pipx install MozPhab

Checkout the source code $ mkdir tb-build && cd tb-build $ hg clone https://hg.mozilla.org/mozilla-central source/ $ cd source/ $ hg clone https://hg.mozilla.org/comm-central comm/

Run the bootstrap command from the source directory. Choose 2 (to build Firefox for Desktop). Choose all of the default options. $ ./mach bootstrap

Make sure your ~/.zshrc has the following line: export PATH="$PATH:/Users/USERNAME/.local/bin"

Create your mozconfig file in the source directory with the following info $ vim mozconfig ac_add_options --enable-project=comm/mail ac_add_options --with-ccache=sccache ac_add_options --enable-clang-plugin mk_add_options AUTOCLOBBER=1

Build Thunderbird! $ ./mach build

Run what you just built! $ ./mach run

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 infrastrtucture 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?

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.

Chapters

00:00 Intro 00:43 Introducing our new Community Manager 07:00 Q1 - Investing in Services AND Desktop and Mobile 15:26 Q2 - Appointment as a stand-alone app 20:46 Q3 - Upcoming features for Appointment 27:56 Q3.5 - Open source paid products 31:29 Q4 - Will Send be part of the core desktop app? 35:13 Q5 - Are there individual file size limits in Send? 43:22 Q6 - Will I be able to use Thundermail with another client? 47:10 Q7 - Are there any plans to expand Thundermail into a Google-like suite? 51:44 Q8 - Will there be public roadmaps for services 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/

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.

Want to learn how to join our recordings and ask questions to our team? Be sure to join the TB planning mailing list using the link in the Resources.

00:00 Intro 02:39 Desktop Roadmap update for Q3 23:28 Dev tools tips and tricks 32:54 Donations, campaign frequency, and revenue health

Resources:

Thunderbird Desktop Roadmap: https://developer.thunderbird.net/planning/roadmap Conversation Add-on: https://addons.thunderbird.net/en-US/thunderbird/addon/gmail-conversation-view/ Release channel blog: https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/ UI/UX mailing list: https://thunderbird.topicbox.com/groups/ux Account Hub video: https://blog.thunderbird.net/2025/04/video-the-new-account-hub/ Eat the Frog summary: https://productivitypatrol.com/eat-the-frog/ State of the Thunder: Volume 1: https://www.youtube.com/watch?v=2xfUO9C_6tw Performance profile how-to: https://support.mozilla.org/kb/profiling-thunderbird-performance 2024 Annual Report blog: https://blog.thunderbird.net/2024/10/thunderbird-annual-report-2023-2024/ Ryan Sipes' GUADEC keynote: https://blog.thunderbird.net/2024/08/thunderbird-goes-to-guadec-2024/ TB planning mailing list: https://thunderbird.topicbox.com/groups/planning

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!

00:00 Intro 01:39 What is ESR? 05:01 How to keep track of channels? 10:05 How to check which channel you're running 11:25 Why the push for the monthly Release channel? 18:22 Why is it called Release channel and not Monthly Release? 21:05 ESR support expectations 24:49 How stable is the Beta channel? 29:03 Can I change channels through a simple update? 33:12 Add-on support in the Release channel 38:53 Highlights of ESR 140 44:41 Community highlight

Resources: What Train is It Now: http://whattrainisitnow.com/ Monthly Release Channel: https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/ Choosing a Release Channel: https://support.mozilla.org/kb/choosing-thunderbird-release-channel Testing Beta Support Article: https://support.mozilla.org/kb/thunderbird-beta Testing Daily Support Article: https://support.mozilla.org/kb/thunderbird-daily Release Channel Support Article (with info on safely downgrading): https://support.mozilla.org/kb/thunderbird-release Add-on Compatibility Add-on: https://addons.thunderbird.net/thunderbird/addon/addon-compatibility-check/ tilorenz's Calendar grid patch: https://phabricator.services.mozilla.com/D251992

In our second Thunderbird + Rust Office Hours, we're taking a deep dive into how we're using Rust in adding Exchange Support. We work through an example of how we send an email utilizing both Rust and C++ to enable this new functionality. As always, we're also answering your questions and letting you know how to get involved.

00:00 Intro 00:32 Microsoft Exchange Support in Rust 02:52 Modern protocol implementation 04:30 Why Rust? 06:06 Why not all in Rust? 08:54 Microsoft Exchange - The Rust side 11:07 Microsoft Exchange - The crates 13:09 Microsoft Exchange - Code infrastructure 26:21 Microsoft Exchange - Types 27:45 Microsoft Exchange - Glue 29:16 Microsoft Exchange - The C++ side 32:28 The future: Testing alpha in daily, stable release, and later 36:49 How you can help 38:38 Question time! 55:09 Final thoughts 58:00 Closing and next office hours

Resources:

If you have access to an Exchange mailbox, please help us test! Report bugs on Bugzilla (https://bugzilla.mozilla.org/enter_bug.cgi?product=MailNews+Core&component=Networking%3A+Exchange), or file them in the “MailNews Core” product, with “Networking: Exchange” as the component, on https://bugzilla.mozilla.org/

Keep an eye on Bugzilla for good first bugs: https://mzl.la/44REhm8

Subscribe to the mailing lists on Topicbox: https://thunderbird.topicbox.com/

Join the Matrix room for Rust in Thunderbird: https://matrix.to/#/#tb-oxidization:mozilla.org

Join the Thunderbird developers room on Matrix: https://matrix.to/#/#maildev:mozilla.org

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, why we're still part of Mozilla, why building Thunderbird is hard (and how we're trying to make it less so), and more!

00:00 Intro 02:25 Monthly releases in Flatpak or Snap 05:50 Accessibility in Thunderbird 15:01 Why is Thunderbird still part of Mozilla? 20:41 Why is building Thunderbird so hard? 34:15 Why does Thunderbird UI sometimes look like Firefox? 38:44 Can I use Git to work on Thunderbird? 39:54 iOS, Android, and Desktop look and features 43:21 Why doesn't Thunderbird offer a fully responsive UI?

Want to know more about the upcoming Thunderbird Pro suite of productivity boosters AND our privacy-focused Thundermail email service? Heather and Monica are chatting with Software Engineer Chris Aquino from our services team to give you a sneak peak at the newest members of the Thunderbird family before they hatch!

00:00 Intro 00:51 What is Thunderbird Pro? 02:07 Appointment: Intro 05:26 Appointment: Who is It For? 10:49 Appointment: Time Zones and Privacy 12:28 Appointment: Using It Without Thunderbird 14:08 Appointment Self Hosting and Open Source Integration 15:22 Thundermail: Intro 19:10 Thundermail: Mobile Support and Custom Domains 21:32 Thundermail: Spam Filtering and Forwarding Plans 22:51 Thundermail: Calendar and Contact Sync 23:57 Send: Intro 26:23 Send: Target Audience 30:33 Send: File Sizes and Expiration 34:35 Send: Balancing Privacy and Safety 44:28 Assist: Intro 46:13 Assist: Semantic Search and Privacy 49:40 Assist: Who is It For? 51:54 Assist: How to Enable and Use It 54:06 Assist: Training the AI 59:41 Assist: Language Support 60:36 Assist: Q&A 74:16 Wrap Up and Future Plans

Resources: ZDNet review of Appointment: https://www.zdnet.com/home-and-office/work-life/the-new-thunderbird-appointment-tool-is-thoroughly-impressive-and-free/ TB Pro Announcement: https://blog.thunderbird.net/2025/04/thundermail-and-thunderbird-pro-services/ TB Appointment Repo: https://github.com/thunderbird/appointment TB Send Repo: https://github.com/thunderbird/send-suite Thundermail Beta Sign Up: https://thundermail.com/ Stalwart: https://stalw.art/ Flower Intelligence: https://flower.ai/intelligence/ Thunderbird Merch Store (alas, no adult footie pajamas yet) North America: https://mozilla-na.myspreadshop.com/thunderbird?collection=irQGRGIyKo Thunderbird Merch Store Europe and Rest of World: https://mozilla-europe.myspreadshop.ie/thunderbird?collection=PMnUuLrvYM

In this excerpt from our May 2025 Community Office Hours, we discuss one of the products in our upcoming Thunderbird Pro suite: Assist. Launching with email summaries, daily briefs, and semantic search, this AI-assistant will feature end to end encryption and remote confidential computing while we work towards the ability for it to run entirely locally.

In this excerpt from our May 2025 Community Office Hours, we discuss one of the upcoming products from our Thunderbird Pro suite: Send! Based on Firefox Send, this service will help you send files, small and large, securely and privately, through Thunderbird and a web app. We discuss what you can expect, and how we intend to make the service succeed for the long term.

In this excerpt from our May 2025 Community Office Hours, we discuss the features planned for our upcoming Thundermail email service! Built with Stalwart and featuring EU hosting, IMAP and JMAP support, and encryption at rest, find our about our privacy-respecting, open source email provider, hatching soon!