Don't delete it

Found another issue
Field Email is Checked as Mailback and Mailback as sender. Is it possible to set, that mail.html.php use mailback as sender, and mailbacktpl.html.php use our default email. Why?
As it is set now, submitter of form receives email confirmation as from his mail, cause mailback as sender is checked. Sure is more professional if he would receive email confirmation from email of a site, where he submitted data.
Thank you