adnsheloex: 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 Debian possible default full paths are:

/usr/bin/adnsheloex - from package: adns-tools

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

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