iRedMail uses PostfixAdmin as web-based admin panel for MySQL backend, but it can't manage BCC maps. We will make iRedAdmin-Pro support MySQL backend in v1.4.0.
Currently, you can use phpMyAdmin or mysql command line to manage bcc maps.
For MySQL structure, refer to this file: http://iredmail.googlecode.com/hg/iRedM … edmail.sql
You can insert proper values into table 'vmail.sender_bcc_user' and 'vmail.recipient_bcc_user' for per-user bcc. Example:
mysql> INSERT INTO sender_bcc_user (username, bcc_address, domain) VALUES ('user@example.com', 'boss@domain.ltd', 'example.com');
This will bcc all mails sent by 'user@example.com' to 'boss@domain.ltd'.