notify: 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:

/var/spool/hylafax/bin/notify - from package: hylafax+

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

On Debian possible default full paths are:

/var/spool/hylafax/bin/notify - from package: hylafax-server
/usr/bin/notify - from package: ruby-notify

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

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