I wish that Debian installer (and other distributions) would have encryption on as default, especially if the installer ask you if you intend to install it as a mail server. Users are entrusting their communication to the server which means that the sane defaults should address their need for privacy and control.

Law enforcement always operate on what is easiest and cheapest. A common practice seem to have been established to raid a data center and take anything that could be valuable and then have it put on the backlog to be sorted in the next 5 years or until statute of limitations. By adding encryption to the situation, its possible to change the economics so its more economical to go through a judge and compel the service provider to provide the specific record that is being requested.