AJAX form submitted to PHP that does not return the correct data

I have a form that I would like to send data from to a php script using AJAX. However I am running into an issue with actually passing the data across. The $_POST array is empty for some reason.

Currently the HTML is:

<form>
    <label>Email Address:</label>
    <input type='text' name='email' value='jackc@test.com'/>
    <input type='submit' name='submit' value='Check subscription status'/>
</form>

The JQuery is:

 $(document).ready(function() {
        $('form').submit(function(e){
            e.preventDefault();
            var url = 'request.php';
            $.ajax({
                type: 'POST',
                url: url,
                contentType: "json",
                data: $('form').serialize(),
                success: function(data){
                    console.log(data);
                    $('#results').html(data);
                }
            });

        });
    });

The PHP is:

        $emailAddress = $_POST['email'];
        echo "EMAIL: " . $emailAddress;

However it's not returning anything. It's blank each time. When I do a console log for $('form').serialize() I see email=jackc%40@test.com which I would expect to see returned from my PHP.

I'd appreciate some help on this. Many thanks.

---

you don't send json data so you need to remove the "contentType" from the ajax request.