Outlook 'delay delivery' option (or whatever your email client supports) is an even better way. If you don't intend someone to read and act on it until morning, you can enforce that trivially!
2) My experience managing and being managed has led me to believe that most managers want their employees to work less, and most people believe that their manager wants them to work crazy hours. Frequently these people are the same people. eg. a middle manager wants his employees to go home and not work after hours, but they assume that their manager expects them to work from home between 7 and 11 PM every night. the GP of your comment even said this - he tells his employees to not work odd hours, but he does so anyway.