It will examine the fields variable first and extract the comma-separated
list of field names from there. Then it will build an email body listing
all the different fields specified like
and send it to the address given in the to parameter, using the
subject line defined in subject and the from address given in
from. It will use a locally installed sendmail process to deliver
After that's done, it will redirect to the URL given in thanks_url,
which will typically just display a ``Thank you!'' page.