3. At the top of the new window, select Outlook Address Book.
4. Check the box that says "Show this folder as an e-mail Address Book". Click OK.
Your chosen contact folder should now appear in the address book. Refer to the next section for more details.
How to access custom contact folders in the address book when sending an email
1. Open a new message and click on the To... button.
2. Under Address Book, select the drop down menu and click the desired contact list in order to view its contents.
3. Contacts within the selected contact folder will then appear. Click the desired contact and Click the To -> button to add them to the To... field. Click OK when done.