zarafa-gateway: 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/zarafa-gateway - from package: zarafa-gateway

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

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