Debian does not enable any system locales by default. You must enable
appropriate locales in dpkg-reconfigure locales. Gettext
translations don't work on glibc systems when system locale is not
available.
Sun gettext libraries use locale name set in successful php setlocale() function call. SquirrelMail 1.4.3a and later versions use locale name with charset information and stores locales in directories without charset information. You must rename directories and include charset information in it or create symbolic links with charset information or disable all $languages[xx_XX]['LOCALE'] code in functions/i18n.php or recompile php to use GNU Gettext libraries.
You must set language environment variables in order to use translations. SquirrelMail does not set them when php is running is safe mode.
You must set language environment variables in order to use translations. SquirrelMail does not set them when php is running is safe mode.