cyrus-imspd: 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/sbin/cyrus-imspd - from package: cyrus-imspd

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

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