x-smile_delta: 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 Debian possible default full paths are:

/usr/lib/mlv-smile/bin/x-smile_delta - from package: mlv-smile

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

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