mcsender: 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/mcsender - from package: smcroute

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

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