Simple email list setup

[Larry Cook]

I am looking for suggestions on setting up a simple announcement email 
list with about 50 static members (no self-subscribe/unsubscribe), of 
which only 4 members can send to the list.  Currently the list is 
managed by one member from her email account.  The two reasons for 
making a change are:

1) The list maintainer doesn't always remember to use bcc to hide 
members addresses.

2) In her absence email cannot be sent to members.

I've used majordomo many years ago and currently use Dada Mail for 
another organization.  I've also looked at Mailman, phplist, poMMo, etc. 
  All of these provide a lot of nice features but they all seem to be 
overkill for our minimal requirements.

Are there any open source packages that just provide the basics we need 
and would be easier to setup and use?

It seems like email aliases with a way to restrict the sender should be 
sufficient.  Are there easy ways to implement this, or something like it?

Thanks,
Larry