Understanding Email Groups
The Email Group application enables you to create new email groups and add or remove individuals from groups.
You create new email groups in two steps: first create the group, and then add to the group the subgroups or individuals who will be included in the email's distribution when it is sent.
If you are adding one or more subgroups to a new group, it might be helpful to think in terms of hierarchy. For example, suppose you want to create a group that includes the entire sales force. The Entire Sales Force email group might consist of groups for the southern, northern, eastern, central, and western regions. However, there might be times when you want to send emails only to the western and northern sales regions, so you would still need to maintain those smaller email groups in addition to the group that includes the whole sales force.