tagtest: 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/tagtest - from package: hylafax+

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

On Debian possible default full paths are:

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

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

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