Before sending an email group, click the "Gmail Plugin for General Contacts" icon to check who's in the group. To add members by selecting contacts to add to the group, click the shortcut icon and then click the name of an existing group in the list. Go to the Admin console > Groups > Create a new Gmail group and add the members you want by simply entering their email addresses. Select Domain Groups from the drop-down menu and click the group you want to send email to.