If you are sending an email out to a few people or a mailing list, you probably are wanting to hide the list of addresses from each recipient. You do this by using the blind carbon copy field in the message you are creating. Outlook has this field hidden by default, to unhide the field, follow these steps:
1. From the Outlook toolbar, click New and select Mail Message.
2. A new message window will appear.
3. Go to the Ribbon and select the Options tab.
4. In the Fields section, select Show Bcc.
5. The Bcc field will appear. Place the address(es) you wish to send a blind carbon copy.