I am not certain that they read the forums, but I can submit your feedback internally to the powers that be and see what happens.  
In OpenManage Essentials, email alerts were sent as plain text, and you could customize the entire message.  In OpenManage Enterprise, you can still customize to some degree, but that's is just the message portion. The message is then wrapped in a huge HTML email with lots of other non-customizable information. We're sending emails to OpsGenie for alert handling, and these massive HTML emails gets really hard to read, with lots of unnecessary information. Can we please have an option to send plain text emails, and be able to customize the entire message please?
Plain text email notifications