BCC, an acronym for blind carbon copy, is a copy of an email sent to a recipient without the recipient's address appearing in the message where other recipients can view it. This is considered the correct way of sending email to multiple recipients when it is likely that the recipients do not know each other and may prefer that their email addresses are not viewable to others.
With Outlook Express, you have two choices for using BCC:
You can display the BCC line in Outlook Express. Click on View on the menu bar of your message, and then click on All Headers. You'll then have a BCC line that you can use.
Your other choice would be to type all the email addresses in the CC line, and surround them with parenthesis,
In email programs that do not have a BCC line, input email address in the CC line and surround them with parenthesis.