Groups for Business
   https://sites.google.com/a/googleapps.com/deploy-google-apps/apps/Groups%20for%20Business%20setup%20guide%20for%20admins.pdf?attredirects=0&d=1


What you can do with Google Groups for Business

Let users build their own email lists

Send messages to teammates, customers, or other working groups using a single mailing list address. Optionally, let users create and manage lists that everyone can share.

Set up collaborative mailboxes

Collaborate on field support tickets or inquiries from customers or employees. Group members can browse, categorize, assign, and reply to messages.

Host community web forums

Allow customers or members of an online community to discuss topics and resolve problems with each other. Forums can be restricted to your organization or open to external participants as well.