<section class="newsletter">
    <h3> Newsletter </h3>
    <p> Receba todas as novidades </p>
    <form method="post" id="newsletter" name="cadastroNews" action="NewsCad.php">
        <input type="text" name="nome" placeholder="Digite seu nome" required>
        <input type="email" name="email" placeholder="Digite seu email" required>
        <input type="submit" name="Enviar" value="Cadastrar">
    </form>
</section>

<?php

  $host = '127.0.0.1:3306';
  $user = 'root';
  $password = 'bruxaria';
  $database = 'quebrandotabus';

  //Conectando ao banco de dados
  $conn = mysqli_connect($host, $user, $password, $database)
              or die(mysql_error());

?>

<?php

include_once("Conexao.php");

    $nome = filter_input(INPUT_POST, 'nome', FILTER_SANITIZE_STRING);
    $email = filter_input(INPUT_POST, 'email', FILTER_SANITIZE_EMAIL);

    $result_usuario = "INSERT INTO newsletter (nome, email) VALUES ('$nome' , '$email')"
                    or die(mysql_error());
    $resultado_usuario = mysqli_query($conn , $result_usuario);

?>