On the Contact Group tab, in the Members group, click Add Members, and then click From Outlook Contacts or From Address Book.Add an address from an address book or a contacts folder.NOTE In list views, Contact Groups are marked with the Contact Group icon. NOTE After the list is expanded, you can’t collapse the list again in that message.
In Contacts, on the Home tab, in the New group, click New Contact Group.Create a Contact Group with new names or names in the Address Book.There is no maximum number of names that you can include in a Contact Group. You can include Contact Groups in email messages, meeting requests, task requests, and in other Contact Groups. A message sent to a Contact Group goes to all the recipients listed in the group.
A Contact Group, known in previous Microsoft Outlook versions as a distribution list, is the grouping of email addresses into a group.