SNPOST: 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/SNPOST - from package: sn

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