Regardless of if you encrypt it or not, to the school it is still going to be against the rules. You are still sending it to their email, which someone else may

Regardless of if you encrypt it or not, to the school it is still going to be against the rules. You are still sending it to their email, which someone else may have access to. If they have access to the computer they may also have access to encryption keys, etc. Even though it is terrible I would just stick with the schools system.