new: 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/mh/new - from package: nmh

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

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