turba-import-squirrelmail-sql-abook: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/turba-import-squirrelmail-sql-abook - from package: php-horde-turba

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/turba-import-squirrelmail-sql-abook - from package: php-horde-turba

You may install the required package with command apt-get install {package}

Error in other languages:
turba-import-squirrelmail-sql-abook: bevel nie gevind nie
turba-import-squirrelmail-sql-abook: comandă negăsită
turba-import-squirrelmail-sql-abook: comando não encontrado
turba-import-squirrelmail-sql-abook: commande introuvable
turba-import-squirrelmail-sql-abook: command not found
turba-import-squirrelmail-sql-abook: käsku ei ole
turba-import-squirrelmail-sql-abook: không tìm thấy lệnh
turba-import-squirrelmail-sql-abook: komanda nerasta
turba-import-squirrelmail-sql-abook: Kommando nicht gefunden.
turba-import-squirrelmail-sql-abook: kommandot finns inte
turba-import-squirrelmail-sql-abook: komut yok
turba-import-squirrelmail-sql-abook: nie znaleziono polecenia
turba-import-squirrelmail-sql-abook: níor aimsíodh an t-ordú
turba-import-squirrelmail-sql-abook: no se encontró la orden
turba-import-squirrelmail-sql-abook: no s'ha trobat l'ordre
turba-import-squirrelmail-sql-abook: opdracht niet gevonden
turba-import-squirrelmail-sql-abook: parancs nem található
turba-import-squirrelmail-sql-abook: perintah tidak ditemukan
turba-import-squirrelmail-sql-abook: príkaz nenájdený
turba-import-squirrelmail-sql-abook: příkaz nenalezen
turba-import-squirrelmail-sql-abook: команда не найдена
turba-import-squirrelmail-sql-abook: командата не е открита
turba-import-squirrelmail-sql-abook: 命令找不到
turba-import-squirrelmail-sql-abook: コマンドが見つかりません