Then a Judge says that policy is designed to hamper the police and security services based on "reasons" contempt of court and sends a CEO to jail for a month.
A retention period in line with SEC requirements (7 years I believe) might fly but 90 days is to short -also how would you discipline some one for abuse of the email system if the evidence disappears
yes, right. that's fine. they could make the expiration time 7 years and a day.
also, when a company finds itself under investigation in court, the judge can order a temporary halt to the ongoing process of timely email deletion so that a fair discovery process can occur.
i believe there are existing penalties for abusing the email system if evidence disappears. that wouldn't change.