How to Create Undisclosed Recipients in Outlook
Unlike the "To" and "Cc" fields, which are visible to all of the recipients of an email message, email addresses in the blind carbon copy (Bcc) fields are hidden. Microsoft Outlook does not include the "Bcc" field automatically, so users must enable the option from the menu bar to add undisclosed recipients to an email message.
Open Microsoft Outlook. Click "Home," then select "New E-mail" from the toolbar.
Click the "Options" tab on the email message window. Click the "Bcc" button to create a "Bcc" field in the message window.
Click "Bcc..." to find recipients in your address book, or enter the email addresses directly into the "Bcc..." field.