Can't be done in HTML. As it was said before, your form action could be mailto, but that is unreliable, as you never know if the person using the site has the mail client set up on their computer. I know a number of people who use only web-clients for their mail and they will not be able to use such a feedback form.
On the other hand you could process the form on the server and send the email like that. For that you would need to find out what server-side lanugage you have and ask your question in one of the fora that deals with that language.