dnsubmit: 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/dnsubmit - from package: dnet-progs

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

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