One of the best parts of the Sitefinity12.1 release for us was the addition of custom email responses. So in a form that contains the Email field, someone can get a custom email sent back to them! This is especially helpful if your form submission redirects to some landing page instead of a message.
Problem though on an Intranet is using this new EmailTextField is redundant. It's an input[type=text] with a ton of validation and stuff, but we KNOW who the user is.
So the modification below checks to see if the user is authenticated, if they are, it's just a hidden field and no extra bloat. You could though keep this file the same and just name a NEW template like Write.Authenticated.cshtml and pick that in the form control designer.
This is my modification to the default template.
Installation
Add this to ~/Mvc/Views/EmailTextField/Write.Default.cshtml