I'd like to have my Postfix receiving instance always bcc mail for a specific
set of recipients to another , off-site server.
And to do so regardless of the intended 'main' recipient address being 'up' for
receiving @ subsequent Postfix transport delivery targets, or not.
Reading,
https://www.postfix.org/postconf.5.html#always_bcc
straightforward for bcc'ing all.
But I don't immediately see that it support maps.
(1) does always_bcc support maps? (doc or example?)
(2) is there a better alternative that always_bcc for this use?
