I see back in March there was a Contact Form update that states...
"2) [Feature] Added an option to use the email provided by the users in Contact Form as Reply To email for the email that is received by the admin when any visitor submits the Contact Form. This can be configured from the SitePad Editor Contact Form widget."
I am unfortunately not finding anything that allows me to set this. By "SitePad Editor Contact Form widget"... are you referring to "Site Pad>Settings>Contact Form" in the site editor?
I have set the field that are there correctly, however I see nothing that gives me the option to choose the Senders email address as the Reply To address. Yes there is a "From" field, but that does not allow me to select anything that would be the Reply To field form the form, unless there is perhaps a code one enters?