There are three parts to the Address section of an email message:
CC used to stand for Carbon Copy, but no one knows what carbon paper is anymore so it is now referred to as Complimentary Copy. BCC is for a blind copy. Recipients will not see that stringy pasta list of names. Here are a few links to more information.
While the recipients can't see the Bcc list, you can see the list in messages you SENT:
"To see the Bcc addresses for messages that you sent, open the message from the Sent Items folder, then choose Actions>Resend This Message. If you don't see the Bcc box, choose Find>Bcc Field to display it. Another method you can use in the Sent Items folder, is to choose View>Show Fields and add the Bcc field to the current view. You may not be able to see all Bcc recipients that way if the list was a long one.