E-Mail Content Filtering via Exchange

I have a client who trades in stocks. They want to move over to Exchange server. The FCC requires that they monitor their e-mail for content. Is there a way to filter every outbound e-mail to look for “hot words” and if “hot words” are within the e-mail, route that e-mail to a designated in-box for approval before sending? I’m hoping for a solution native to exchange but am open to third party suggestions.