prevent webform from storing user input
You can edit the form with function_form_alter(), and modify what to do on submit. Try this:

function MY-MODULE_form_alter(&amp;$form, &amp;$form_state, $form_id){
  if( $form_id == 'YOUR-FORM-NAME' ){
    $form['actions'][]= array(
      '#submit' =&gt; array('_CUSTOM_FUNCTION')
    );
  }
}
function _CUSTOM_FUNCTION(){
  //put what to do here
}