Yay!
# grep header_checks /etc/main.cf
header_checks = regexp:/etc/postfix/header_checks
Then
# cat /etc/postfix/header_checks
/^Subject:.*R0407z2 postfix$/ REDIRECT root@localhost
finally
# postfix reload
Now every mail subject ending with “R0407z2 postfix” will be redirected to root@localhost, the original recipient won’t receive the mail.
You can reject, hold, redirect the mail etc. All you need is here and there.
