Thunderbird Pro August 2025 Update
In April of this year we announced Thunderbird Pro, additional subscription services from Thunderbird meant to help you get more done with the app you already use and love. These services include a first ever email service from Thunderbird, called Thundermail. They also include Appointment, for scheduling meetings and appointments and Send, an end-to-end encrypted filesharing tool. Each of these services are open source, repositories are linked down below.
Thunderbird Pro services are being built as part of the broader Thunderbird product ecosystem. These services are enhancements to the current Thunderbird application experience. They are optional, designed to enhance productivity for users who need features like scheduling, file sharing and email hosting, without relying on the alternate platforms. For users who opt in, the goal is for these services to be smoothly integrated into the Thunderbird app, providing a natural extension of the familiar experience they already enjoy, enhanced with additional capabilities they may be looking for. For updates on Thunderbird Pro development and beta access availability, sign up for the mailing list at thundermail.com.
Progress So Far
Thundermail
Development has been moving steadily forward and community interest in Thundermail has been strong. The upcoming email hosting service from Thunderbird will support IMAP, SMTP and JMAP out of the box, making it compatible with the Thunderbird app and many other email clients. If you have your own domain, you’ll be able to bring it in and host it with us. Alternatively, grab an email address provided by Thunderbird with your choice of @thundermail.com or @tb.pro as the domains. The servers hosting Thundermail will initially be located in Germany with more countries to follow in the future. Thunderbird’s investment in offering an email service reflects our broader goal of strengthening support for open standards and giving users the option to keep their entire email experience within Thunderbird.
Thunderbird Appointment (Repo)
We originally developed the scheduling tool as a standalone web app. On the current roadmap, however, we’re tightly integrating Appointment into the Thunderbird app through the compose window, allowing users to insert scheduling links without leaving the email workflow. It will be easy for organizations and individuals to self-host, fork and adapt the tool to their own needs. The future is for Appointment to support multiple meeting types, like Zoom calls, phone meetings, or in-person coffee chats. Each of these will have its own settings and scheduling rules.
One of the most requested future features is group scheduling, which would allow multiple team members to offer shared availability via a single link. The current calendar protocols don’t fully support this flow, however Thunderbird is participating in discussions around open standards like VPOLL to help move things forward. Usability studies are helping refine the MVP and community feedback is shaping the roadmap.
Thunderbird Send (Repo)
A secure, end-to-end encrypted file sharing tool, built on Thunderbird app’s existing Filelink feature. It supports large file transfers directly from the email client. This allows users to bypass platforms like Google Drive or OneDrive. Pro users will receive 500 GB of storage to start, with no individual file size limit, only constrained by their total quota. We’re planning support for chunked uploads and encryption to ensure reliability and data protection. We’ll deliver Send as a system add-on which lets the team push updates faster. This also avoids locking new capabilities behind major Thunderbird release cycles.
All Thunderbird Pro tools are open source and self-hostable. For users who prefer to run their own infrastructure or work in regulated environments, both Send and Appointment can be deployed independently. Thunderbird will continue to support these users with documentation and open APIs.
A Look Ahead
Thunderbird is exploring additional Pro features beyond the current lineup. While we’ve made no commitments yet, there is strong interest in adding markdown based Notes functionality, especially as lightweight personal knowledge management becomes more popular. Heavier lifts like collaborative docs or spreadsheets may follow, depending on adoption and sustainability.
Another worthy mention: a fourth, previously announced service called Assist, which will eventually enable users to take advantage of AI features in their day-to-day email tasks, is still in the research and development phase. It will not be part of the initial lineup of services. This initiative is a bigger undertaking as we ensure we get it right for user privacy and make sure the features included are actually things our users want. More to come on this as the project progresses.
To improve transparency and invite community collaboration, Thunderbird is also preparing a public roadmap covering desktop, mobile and Pro services. We’re developing the roadmap in collaboration with the Thunderbird Council. Our goal is to encourage participation from contributors and users alike.
Free vs Paid
Adding these additional subscription services will never compromise the features, stability or functionality our users are accustomed to in the free Thunderbird desktop and mobile applications. These services come with real costs, especially storage and bandwidth. Charging for them helps ensure that users who benefit from these tools help cover their cost, instead of donors footing the bill.
Thunderbird Pro is a completely optional suite of (open source) services designed to provide additional productivity capabilities to the Thunderbird app and never to replace them. The current Thunderbird desktop and mobile applications are, and always will be, free. They will still heavily rely on ongoing donations for both development and independence.
If you haven’t already, join our waiting list to be one of the early beta testers for Thunderbird Pro. While we don’t have a specific timeline just yet, we will be sharing ongoing updates as development progresses.
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Ryan Sipes
Managing Director, Product
Mozilla Thunderbird