mlmmj-sub: 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 CentOS possible default full paths are:

/usr/bin/mlmmj-sub - from package: mlmmj

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/mlmmj-sub - from package: mlmmj

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

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