What Thunderbird users can expect in 2026: database overhaul and iOS app

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The Thunderbird team has published a comprehensive annual review, summarizing the most important developments of 2025. At the same time, the team provides an outlook on planned changes for 2026. A key innovation in 2025 was the switch to monthly updates – new features and bug fixes now reach users significantly faster than with the previous annual rhythm.

Thunderbird Pro to launch in Early Bird phase in 2026

The start of the Early Bird beta of Thunderbird Pro is planned for the first half of 2026. The paid package includes three services: Thundermail for email hosting, Appointment for scheduling, and Send for end-to-end encrypted file sharing. An introductory price of $9 per month is being tested during the internal trial phase. The plan includes 30 GB of mail storage, 300 GB for Send, 15 email addresses, and 3 custom domains. Particularly relevant for German users: the Thundermail infrastructure will be hosted in Germany or the EU.

Thundermail relies on established protocols such as IMAP, SMTP, and the more modern JMAP. The latter promises more efficient synchronization than classic IMAP and will also play an important role for smartphone apps. The encrypted file sharing service Send has already undergone an external security audit, the report for which is still in the correction phase.

With Thunderbird Pro, the project is pursuing a new financing approach. Previously, Thunderbird was mainly financed by donations. The recurring revenue from subscription models is intended to secure long-term development, infrastructure, and security audits. However, the team emphasizes that desktop and mobile apps will remain free permanently. Thunderbird Pro also promises never to sell user data or display ads, unlike commercial providers such as Google Workspace or Microsoft 365.

Database modernization and mobile platforms

For 2026, the developers also announce a fundamental modernization of the desktop database, which has been in use for decades. The goal is to improve stability, performance, and scalability. However, the team did not provide concrete technical details on the implementation in the blog post. The overhaul should lead to noticeable improvements, especially with large mail archives.

On the mobile front, Thunderbird made progress on Android in 2025 and launched initial developer builds for iOS. For 2026, the team plans a re-architecture of the old code of the Android client with more frequent small updates and a modernized user interface. The iOS app will initially rely on proven protocols; IMAP is the priority, followed later by JMAP, CalDAV, and CardDAV. The focus on IMAP is due to the widespread adoption and reliability of the protocol on Apple devices.

Open questions about Exchange and Microsoft Graph

While the integration of the Exchange Web Services (EWS) protocol is an important step for Exchange users, the future of the interface remains open. Microsoft plans a long-term migration to its Graph API. Thunderbird mentioned Graph as a potential future option; it is not yet implemented but should be faster to implement than EWS support. For companies looking for a complete replacement for the data-kraken Outlook, central functions such as calendar synchronization, address books, and meeting management via Exchange are currently missing.

The calendar interface is also scheduled for a redesign in 2026. As soon as calendar functionality is added to the Exchange integration, users will receive a modernized user experience. When exactly this extension will arrive, the project left open, as well as a detailed technical roadmap for 2026, which is usually published in January.

(fo)