sendpage: 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/bin/sendpage - from package: hylafax+-client

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

On Debian possible default full paths are:

/usr/bin/sendpage - from package: hylafax-client
/usr/sbin/sendpage - from package: sendpage-server

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

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