confirmation_template       - If this field is set then it must be the
                              name of an email template that will be used
                              to send a mail back to the user confirming
                              their submission.  CAUTION: since the user
                              could give any email address (not just their
                              own) and submit repeatedly, there is a risk that
                              some nasty person will use this to mailbomb
                              a third party.  Only switch this on if you
                              really need it.  Template directives that
                              depend on user input will be disabled for this
                              template, so that this feature can't be used to
                              send SPAM.  Default: no confirmation email.