amavisd-new: 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/sbin/amavisd-new - from package: amavisd-new

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