Custom Email Templates for Any Email Notification Available

Hello!

I know there is functionality on creating email templates for events, but it would be good if, wherever an email configuration is being available, to define how the email should look like. 

For example, the test email when configuring email settings does not contain much information about from what system this is coming (Server, etc.). 

The email that is sent when data is not received provides some info, but it would be good to customize that somehow, maybe with further information available in the system. 

Thanks