Since Tails 7.5 (February 2026), Tails tries to automatically install *Thunderbird* as [[additional software|persistent_storage/additional_software]] to improve its security.
A new version of *Thunderbird* is released in Debian shortly after each Tails release, because both *Tails* and *Thunderbird* follow the [[release calendar of *Firefox*|https://whattrainisitnow.com/calendar/]]. As a consequence, until Tails 7.5 (February 2026), the version of *Thunderbird* in Tails was almost always outdated, with known security vulnerabilities.
By installing *Thunderbird* as additional software, the latest version of *Thunderbird* is installed automatically from your Persistent Storage each time you start Tails.
Tails also tries to install as additional software the language package that corresponds to the language of your first session with Tails 7.5 or later. To use *Thunderbird* in another language, see how to [[use *Thunderbird* in another language|thunderbird#language]].