E-mail recipients who are listed in the BCC box can be viewed by e-mail recipients who are listed in the To and CC boxes when you send a multi-part e-mail message by using Outlook Express 6.0
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/34159/outlookNoBCC.html
Source: https://packetstormsecurity.com/files/34159/outlookNoBCC.html.html