ndsend: 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/sbin/ndsend - from package: vzctl

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

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