sndelgroup: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/sbin/sndelgroup - from package: sn

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