Process Model alerts subject/body configuration

The alert will use (as far as i remember) the environment's name as set in the cloud configuration - assuming you're using Appian Cloud and your alert emails are insufficiently differentiated, i'd suggest you open a support case asking them to set the configuration parameters on your different environments to something you can discern from the email header (in my case, the senders are labelled differently in such a way that you can tell just by viewing the email in your inbox).