icedove-l10n-br software package provides Breton language package for Icedove, you can install in your Debian 8 (Jessie) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install icedove-l10n-br
icedove-l10n-br is installed in your system.
Make ensure the icedove-l10n-br package were installed using the commands given below,
$ sudo dpkg-query -l | grep icedove-l10n-br *
You will get with icedove-l10n-br package name, version, architecture and description in a table
| Distro | Debian 8 jessie |
| Section | Language packs |
| Package | icedove-l10n-br |
| Version | 1:45.4.0-1~deb8u1 |
| Description | Breton language package for Icedove |
| Sub Section | localization |