ondelay: 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 CentOS possible default full paths are:

/usr/sbin/ondelay - from package: hylafax+

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/ondelay - from package: hylafax-server

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

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