I set a mail flow rule in Exchange 2016 which scans the subject and body for a keyword (scarecrow for testing) and if found, sends a bcc of the E-mail to another internal E-mail recipient on my mail server. The rule works fine for E-mail sent internally or E-mail sent out to an external address. The rule does not apply to inbound E-mail whether newly created or in the form of a reply from an external address.
I don't see a method of creating a mail flow rule to inspect incoming messages, maybe I'm missing it. Is there another way for Exchange (Not the individual Outlook clients) to detect a keyword in the subject line or body of an incoming E-mail and bcc a copy of the incoming E-mail to a second internal address?