I have 2 servers, one in production and other one in lab. In both servers I configured bcc to all incoming and outgoing messages, according to the instructions obtained at this forum.
All outgoing messages are copied to the respective bcc account (defined on sender_bcc_maps in main.cf), but recipient_bcc_maps doesn't work.
The hash:/opt/zimbra/postfix/conf/redirect_bcc is the same file to both bcc_maps with this content:
usuario@dominio.com.br <TAB> usuariocc@dominio.com.br
teste@dominio.com.br <TAB> testecc@dominio.com.br
I made another test, disabling recipient_bcc_maps and enabling always_bcc, and this works fine to all incoming messages, but to one single account.
The log file doesn't have any information about this.

Tks,
MMedinaBR

Release 5.0.14_GA_2850.DEBIAN4.0 DEBIAN4.0 FOSS edition