faxadduser: 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/faxadduser - from package: hylafax+

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

On Debian possible default full paths are:

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

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

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