The BCC header is optional. It rarely appears as a header within
received e-mail (and is considered a violation or from a broken mail
server if it does appear). When you send 100 copies of the same e-mail,
the aggregate of the To, Cc, and Bcc headers are used in issuing
separate RCPT-TO commands to the SMTP server; i.e., the recipients are
designated by your client telling the SMTP server where to send the
e-mail, not by listing them within the *data* of the message. The To,
Cc, Bcc, Subject, and Reply-To headers are optional; they may appear
zero or one times. They are part of the *data* that the sender includes
in their message. Most e-mail clients will not include the BCC header
in the data (and a good SMTP server would strip it out before sending
the e-mail). Because these fields are part of the data of the message,
and since it is whatever the sender wants to include and specify for
values, this is how spammers use bogus To and From headers because they
had nothing to do with the actual commands issued to the SMTP server to
tell it where to deliver the e-mail.
It is highly unlikely that the BCC header is anywhere in the header
section of any e-mail you receive. You cannot display it because it is
not there.
If you want to see through which account an e-mail was received in
Outlook then add the "E-mail Account" column. If you have N e-mail
accounts defined in Outlook, then that one column will show you through
which e-mail account each message was received. You would think that
Microsoft would have included this under View -> Options to see the
account used to receive the message, but they don't. So adding the
column (or using a rule that uses the account name to move the message
into a different folder) are the only ways that I've found within
Outlook to identify the receiving account for a message.