snpp: 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/bin/snpp - from package: sendpage-client

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

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