imap sharing debian list mail for multiple users

[Mark Devin <mdevin@ozemail.com.au>]

Here is the problem:

Say you have multiple users on your system and they all like to read the
debian-user mailing list.  Now if they all subscribe to the list for
their own personal copies of each mail then this increases the load on
the server.

What would be a better approach would be to have an imap account which
receives all debian-user mail and each user can map this account using
their favourite mail client.  Obviously, users shouldn't be able to
delete or move mail from this list as this might upset other users.

What are the solutions to this problem?  I have noticed that some people
frquenting this list have email addresses like: debian@example.com.  Is
to address this issue?

Currently, I use fetchmail, postfix, procmail, and courier-imap. 
postfix and courier-imap authenticate via my ldap server.

Regards.
Mark.