Custom Email for Admin communication from Server (Specifically for email boxes when they are approaching limits)

It would be fantastic to have the ability to allow an override for emails sent by the server which monitor limits. Specifically on emails.

Currently the email is set from the server, using the server host record ie root@hostname.com 

We would like to be able to

1. Add a custom from name and email
2. Customise the message the users receive when receiving the email concerning account limits. Current email is too generic and makes no sense to the user as to how they can complete or sort out the issue

Thanks.