BuddyPress Group Newsletter plugin by svenson allows the admin or moderator to send an email to all group members. As a member of a group you can view all newsletters.
BuddyPress is an open source social networking software package. It is a plugin that can be installed on WordPress to transform it into a social network platform. BuddyPress is designed to allow schools, companies, sports teams or any other niche community to start their own social network or communication tool.
Download: http://wordpress.org/extend/plugins/buddypress-group-newsletter/
