chk_cyrus: 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/chk_cyrus - from package: cyrus-common

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

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