spamtrap: 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
/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/spamtrap - from package: dsbltesters

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