bcc: would see the to: and cc: addresses and only its own bcc: address
to: and cc: would not see any of the bcc: addresses
from:'s copy of the email would show every address - to:, cc:, bcc:
http://email.about.com/od/emailnetiq...cc_and_bcc.htm
I found out some really surprising info about bcc addresses few years ago.
The email message actually gets sent out with ALL the addresses (to:, cc:, bcc: ) attached. Something to do with SMTP protocol.
When it's gets to each recipient's mail server, then the other addresses are stripped out before being forwarded to individual mailboxes.
So technically, that individual email you received was sent to you with all the bcc addresses, but you never see them.
However, if a to: recipient had access to the mail server, it would be possible to view the bcc: addresses.
For 99% of the people who use bcc:
s, it is blind and works fine.
But in terms of legal, business and/or marital issues ;-) , you should just be aware there is a trail. And it is trackable. ;-)