# Thunderbird email client software expansion > Live situation record from CLSTR: https://clstr.news/situations/thunderbird-email-client-software-expansion > Updated: 2026-10-01T23:14:11.000Z. Sources: 4. Developments: 2. The Thunderbird email client has expanded its accessibility through new software releases. Initially, portable versions of the Thunderbird ESR (Extended Support Release) were released via PortableApps.com. These editions are designed for use in large organizations, such as businesses and government entities, allowing users to run the software from USB drives or mobile devices without leaving personal information on host machines. Following this, Mozilla announced the development of a native Thunderbird application specifically for iOS devices, including iPhone and iPad. Unlike the existing Android version, this new app is being built from the ground up to improve speed and integration with Apple hardware. Planned features include automated account setup, background synchronization to preserve battery life, and a streamlined inbox layout. The development process will utilize an experimental feature flag system to allow community testing and open-source contributions. ## Timeline ### 2026-10-01: Mozilla develops native Thunderbird email app for iOS Mozilla is building a native Thunderbird email app for iOS from the ground up, featuring automated account setup and background sync, with community testing expected in the coming months. 2 sources. https://clstr.news/cluster/mozilla-develops-native-thunderbird-email-app-for-ios ### 2026-09-07: Thunderbird releases portable versions of email client New portable versions of the Thunderbird email client have been released, including an Extended Support Release (ESR) optimized for mobile use and large organizations via the PortableApps.com platform. 2 sources. https://clstr.news/cluster/thunderbird-releases-portable-versions-of-email-client --- Cite as: Thunderbird email client software expansion. CLSTR, https://clstr.news/situations/thunderbird-email-client-software-expansion