Your entire form must be inclosed in <form> tags.
<form> . . . actual form content goes here . . . </form>
Once you have created a frame for your form, you must determine what will be done with it once it has been submitted. This is done with action and method attributes. The action attribute points your browser to a file that contains processing instructions, and the method attribute determines how your browser will interact with that file.
Formmail requires the action to point to /cgi-bin/formmail.pl and that the method be post, so your form will actually look like this, if located in your www directory.:
<form action="/cgi-sys/formmail.pl" method="post"> . . . actual form content goes here . . . </form>