I have a requirement to always_bcc except when email is internal. I have investigated options such as always_bcc, sender|recipient_bcc_maps and none seem to fully address the issue.
Sample scenario. My domain is example.com; when a email's RECIPIENT and SENDER are both @ example.com then process email WITHOUT forwarding a copy to arch...@archive.example.com. IF the email's RECIPIENT and / or SENDER are not @example.com then process email AND forward a copy to arch...@archive.example.com. Is this possible with postfix, postfix filters, and / or postfix + procmail? Thank you! Eric