amavis-mc: 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/amavis-mc - from package: amavisd-new

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