clone_member: 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/lib/mailman/bin/clone_member - from package: mailman

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

On Debian possible default full paths are:

/usr/lib/mailman/bin/clone_member - from package: mailman
/usr/sbin/clone_member - from package: mailman

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

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