BCC addresses shown to TO and CC people also.

I encountered this problem as bcc field are shown to To and
CC people
also which is not right. How can I help it out.

I did a quick test and it works fine for me. I sent an email
with
Address 1 in the To: field and Address 2 in the BCC field.

I got the email at both addresses but the only one showing
was the one
in the To: field, which is how it should work.