HTML:
<form class="form-newsletter">
  <div class="form-group form-group-submit-inline">
    <input type="email" name="email" id="email" class="form-control form-control-white">
    <label class="form-label">SEU E-MAIL</label>
	<button type="submit" class="submit-icon"></button>
  </div>
  <div class="clearfix response-form"></div>
</form>



JS:

  // Formulário Newsletter
  $('.form-newsletter').validate({
    errorPlacement: function(error, element) {
      return false;
    },
    rules: {
      email: {
        email: true,
        required: true,
      },
    },
    submitHandler: function(form) {
        $('form').submit(function(){
            var dados = new FormData(this);

            $.ajax({
                url: 'salvar_newsletter.php',
                type: "POST",
                data: dados,
                processData: false,
                cache: false,
                contentType: false,
                success: function( data ) {
                    console.log(data);
                },
                error: function (request, status, error) {
                    alert(request.responseText);
                }
            });
            return false;
          });
    }
  });