[Mailman-Users] best way to make announce list for members of lots of other lists?

[Duane Winner]

Hello,

Question: We host a few dozen lists for clients who run our software. 
Each client has a unique list for their own organization, and it is used 
to correspond with us (the developers), etc., but not with each client.

However, whenever we release a new version of software for ALL the 
clients, we would like an "announce" list, so one of us can post an 
announcement, and all the clients get.

1) Each client should not see who the other clients are.
2) Is there an easy way to take members of the existing lists so extra 
work does not have to be done to populate the announce list with same 
members?
3) Just as an aside, our clients do not subscribe to the lists -- we do 
it for them, and then only give them access to the archives.


Thanks for any info,
DW