tsitest: 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/tsitest - from package: hylafax+

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

On Debian possible default full paths are:

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

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

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