maildiracl: 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/maildiracl - from package: courier-base

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

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