[Mailman-Users] How to configure a mailman list so mailman to not send any messages to this list?

Hi,

i created a list, but i want to configure mailman to not sent any messages to members of this list. I want to use this list as a backup list where to keep all my members. The members must not able to send messages and also mailman must not send messages to them.

How can i do that?

Thanks in advanced!