If you frequently send messages to a specific group of people, such as members of a team you’re on, or family members, you can simplify the process by adding them to a contact group. You can then address a message to the group (rather than to all the individual contacts) and it will go to all the group members.
To create a contact group:
On the Address Book toolbar, click the New arrow and then, in the list, click Group.
In the Group window that opens, enter the group name, and then click the Add button.
In the text box that appears, enter the name (if you have a contact record for the person) or e-mail address of each group member. Press Tab after each entry to start a new line, or Return to finish.
If you want the e-mail messages you send to this group to display only the group name, and not the addresses of the group members, select the Don’t show addresses when sending to group check box.
When you’re done adding members to the group, close the window and, in the message box prompting you to save your changes, click Save.