rumtp: 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/sbin/rumtp - from package: uucp-lmtp

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

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