zarafa-server: 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-server - from package: zarafa-server

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

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