Amavis & postfix always_bcc

[Alex]

Hi,
I'd like to enable always_bcc in postfix so always, well, get a copy
of all email. However, due to the reinjection of the email back to
postfix after it gets scanned, it gets duplicated. Is there a
solution? Can this be done with just amavis?

I have done it in the past with dual postfix instances, but I'm not
doing that on this system.

Suggestions greatly appreciated.
Thanks,
Alex