发送邮件ajax + php

有一个表格，用户在其中选择所需的许可证数量、总费用等，输入姓名、电话号码和邮件，然后将其发送到我的邮箱。问题是只有姓名和邮件字段的信息才能进入邮件，其余的都是空的。

我不明白可能是什么问题，请帮忙）标记：

<form id="contact_form" method="post" action="php/mail.php">
    <input type="button" value="−" id="minus" class="mycount button-minus">
    <p id="count" name="lisence_count" class="mycount simple-count">1</p>
    <input type="button" value="+" id="plus" class="mycount button-plus">
    <input type="text" id="name" name="name" class="myinfo" placeholder="Ваше имя">
    <input type="text" id="phone" name="phone"  class="myinfo" placeholder="Телефон">
    <input type="email" id="email" name="email" class="myinfo" placeholder="Email">
    <button type="submit" id="send-button" class="submit-button">Подключить<span id="current-price" name="price" class="tarif-price">$10</span></button>
    </form>

JS：

$('#contact_form .submit-button').on('click', function() {
            //берем путь php обработчика
            order_url = $('#contact_form').attr('action');
            //посылаем асинхронный запрос на сервер и передаем все данные формы
            $.post(order_url,{
                name: $('#contact_form input[name=name]').val(),
                tel: $('#contact_form input[name=phone]').val(),
                email: $('#contact_form input[name=email]').val(),
                lisence_count: $('#contact_form #count').val(),
                price: $('#contact_form #current-price').val(),
                send: "1"
            }, "html");
        return false;
    });

PHP：

    header('Content-type: text/html; charset=utf-8');
error_reporting(0);

if(!empty($_POST['send'])) {

    $name = substr(htmlspecialchars(trim($_POST['name'])), 0, 300);
    $tel = substr(htmlspecialchars(trim($_POST['phone'])), 0, 100);
    $email = substr(htmlspecialchars(trim($_POST['email'])), 0, 100);
    $lisence = substr(htmlspecialchars(trim($_POST['lisence_count'])), 0, 100);
    $price = substr(htmlspecialchars(trim($_POST['price'])), 0, 100);

    $ip = $_SERVER['REMOTE_ADDR'];


    $mess  = "Имя: <b>".$name."</b><br />";
    $mess .= "Телефон: <b>".$tel."</b><br />";
    $mess .= "Email: <b>".$email."</b><br />";
    $mess .= "Количество лицензий: <b>".$lisence."</b><br />";
    $mess .= "Цена: <b>".$price."</b><br />";


    mail("thisismymail@gmail.com", $theme, $mess, "From: GSuite \nContent-Type: text/html;\n charset=utf-8\nX-Priority: 0");

}
else {

    echo "<h2>Ошибка! Попробуйте еще раз.</h2>";

}