Encrypted email message structures can contain recipient information that
can reveal, to any recipient, all of the other recipients of an email
message. Because some recipients, such as recipients to whom the message
was "blind carbon-copied", should remain hidden from the other
recipients, individual encrypted messages can be created. One encrypted
message can be created for all of the recipients who are intended to be
revealed, such as the recipients listed in the TO and CC fields of an
email header. A second encrypted message can be created for all of the
recipients of the message who are intended to be hidden, such as the
recipient listed in the BCC field of an email header. Alternatively,
multiple encrypted messages can be created individually for each
recipient in the BCC field, if the BCC recipients are to be hidden even
from other BCC recipients.