recipient_bcc,sender_bcc and always_bcc

>> add the describe into /etc/postfix/mail.cf
recipient_bcc_maps = hash:/etc/postfix/recipient_bcc
>>create file : recipient_bcc
content
123 abc
... ...
>>after that do
postmap /etc/postfix/recipient_bcc
>>make .db file
>>and postfix restart to finished setup

** sender_bcc is similar to recipient_bcc

**all message bcc to admin or someone
>> add the describe into /etc/postfix/mail.cf
always_bcc = admin(someone's account)
>> and postfix restart