[Mailman-Users] Cascading lists

[Rubén Fernández Asensio]

Hello all,
I'm a new list administrator and a bit lost among Mailman's many 
features. Could you please give some advice?
I'm trying to implement an announcement list and an unmoderated 
discussion list, and having the second receive all mail sent to the 
first one. The announcement list will prevent everybody but a few 
addresses to post, and will attach a personalized footer to every post 
with a link to the subscriber's option page. The discussion list will 
attach its own generalized footer.
In sum, I want a single place to manage permissions to send 
announcements to both lists. I don't care about duplicates, as I want 
people to actively unsubscribe from the announcement list if they've 
joined both by mistake. However, it would be nice if the announcements 
received by the discussion list wouldn't have any personalized footer. 
Also, I want subscribers of the discussion list to be able to send 
replies to the announcement into the discussion list itself, whereas 
subscribers of the announcement list will get their own 'Reply-to' heading.
What's the best setup to achieve this? Umbrella lists, sibling lists, or 
something else?

Thanks in advance,
Rubén Fernández