PHP form validation Ajax XMLhttp verzend geen mail naar mijn mailbox.

Het verzenden van een test mail werkt, en ik zie dat hij deze syntax uitvoerd : _("status").innerHTML = '<p>Thanks your message has been sent successfully.</p>';

Ik heb een simpele test mail gemaakt en die getest. In de browser zie ik gewoon dat alles werkt, maar gek genoeg ontvang ik geen mail in mijn inbox. Lopen Googlen en alles getest, zoals uitgebreide headers toevoegen in PHP, maar dat lijkt allemaal niets uit te maken.

<div class="container-fluid">


<form method="POST" action="send_email.php" id="contact-form" onsubmit="submitForm(); return false;">
<h2 id="header-contact">Contact</h2>
<label>
<span class="contact">Your Email</span>
<input id="email" class="contact_input" type="text" name="email" placeholder="[email protected]">
</label>

<label>
<span class="contact">Subject</span>
<input id="subject" class="contact_input contactinfo" type="text" name="message">
</label>

<label>
<span class="contact">Message</span>
<textarea id="message" name="comment" class="contact_input contactinfo"></textarea>
</label>

<label>
<input id="button" type="submit" value="SEND">
<br>
<span id="status"></span>
</label>
</form>
</div>


<?php
if (isset($_POST["email"]) && isset($_POST["subject"]) && isset($_POST["message"])) {
$email = $_POST["email"];
$subject = $_POST["subject"];
$message = $_POST["message"];

$to = "[email protected]";
$from = $email;
$subject = "Contact From Message";
$message = "<b>Email Address:</b> ".$email. " <br><b>Subject: </b> ".$subject." <p> ".$message." </p>";
$headers = 'From: [email protected]' . "\r\n" .
'Reply-To: [email protected]' . "\r\n" .
'X-Mailer: PHP/' . phpversion();
if (mail($to, $subject, $message, $from)) {
echo "success";
} else {
echo "The server failed to send the message. Please try again later.";
}
}
?>

function _(id) {
return document.getElementById(id);
}

function submitForm() {
_("button").disbled = true;
_("status").innerHTML = "Please wait...";
var formdata = new FormData();
formdata.append( "email", _("email").value );
formdata.append( "subject", _("subject").value );
formdata.append( "message", _("message").value );
var ajax = new XMLHttpRequest();
ajax.open("POST", "resume/send_email.php"); // parameter: method, url, boolean (optional)
ajax.onreadystatechange = function() {
if(ajax.readyState == 4 && ajax.status == 200) {
if(ajax.responseText == "success"){
_("status").innerHTML = '<p>Thanks your message has been sent successfully.</p>';
} else {
_("status").innerHTML = ajax.responseText;
_("button").disabled = false;
}
}
}
ajax.send(formdata);
}