master: 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/lib/cyrus/bin/master - from package: cyrus-common

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

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