<p id="returnmessage"></p>
                <br/>

              <div class="form-group row">
                  <label for="name" class="col-sm-4 col-md-4 control-label">Nome</label>
                  <div class="col-sm-8 col-md-6 col-lg-6">
                      <input type="text" class="form-control" id="name" name="name" placeholder="Nome e Cognome">
                  </div>
              </div>

                <div class="form-group row">
                  <label for="email" class="col-sm-4 col-md-4 control-label">E-Mail</label>
                  <div class="col-sm-8 col-md-6 col-lg-6">
                      <input type="email" class="form-control" id="email" name="email" placeholder="example@domain.com">
                  </div>
              </div>

                <div class="form-group row">
                  <label for="message" class="col-sm-4 col-md-4 control-label">Messaggio</label>
                  <div class="col-sm-8 col-md-6 col-lg-6">
                      <textarea class="form-control" rows="4" id="message" name="message" placeholder="Messaggio"></textarea>
                  </div>
              </div>

                <div class="form-group row">
                  <div class="col-sm-8 col-sm-offset-4">
                      <input id="submit" name="submit" type="submit" value="Invia" class="btn btn-primary">
                  </div>
              </div>

            </form>

$(document).ready(function(){
$("#submit").click(function(){
    var name = $("#name").val();
    var email = $("#email").val();
    var message = $("#message").val();

    $("#returnmessage").empty(); //To empty previous error/success message.
//checking for blank fields
if(name==''||email==''||message=='')
{
   alert("Attenzione! Uno o piu campi risultano vuoti");
}
else{
// Returns successful data submission message when the entered information is stored in database.
$.post("contact_form.php",{ name1: name, email1: email, message1:message},
   function(data) {
                $("#returnmessage").append(data);//Append returned message to message paragraph
                    if(data=="Richiesta inviata"){
                        $("#form")[0].reset();//To reset form fields on success
                    }
            });
         }

});
});

<?php
//Fetching Values from URL
$name = $_POST['name1'];
$email = $_POST['email1'];
$message = $_POST['message1'];
$contact = $_POST['contact1'];
//sanitizing email
$email = filter_var($email, FILTER_SANITIZE_EMAIL);
//After sanitization Validation is performed
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {

    $subject = $name;
    // To send HTML mail, the Content-type header must be set
    $headers = 'MIME-Version: 1.0' . "rn";
    $headers .= 'Content-type: text/html; charset=iso-8859-1' . "rn";
    $headers .= 'From:' . $email. "rn"; // Sender's Email
    $template = '<div style="padding:50px; background-color:#ffffff; color:#000;">Richiesta di informazioni tramite il sito villaporticciolo.it<br/><br/><br/>'

    . 'Nome: ' . $name . '<br/>'
    . 'Email: ' . $email . '<br/>'
    . 'Messaggio: <br/><br/>' . $message . '<br/><br/>'
    . '<br/>';

    $sendmessage = "<div style="background-color:#ffffff; color:#000;">" .    $template . "</div>";
    // message lines should not exceed 70 characters (PHP rule), so wrap it
    $sendmessage = wordwrap($sendmessage, 70);

    // Send mail by PHP Mail Function
    mail("example@yahoo.it", $subject, $sendmessage, $headers);
    echo "Richiesta inviata";
}
else {
echo "<span>*Errore di invio, si prega di riprovare*</span>";
}

?>