deliver: 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/deliver - from package: cyrus-common

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

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