PHP Web表单未发送电子邮件

我一直在尝试提交网站表单以发送电子邮件。我已经测试了邮件的工作原理，所以我对自己做错了什么一无所知。请帮忙。

我已经被发送到stackoverflow上的其他PHP提交代码，但它仍然不起作用。

PHP代码：

<?php   
$name = $_POST['name'];
$email = $_POST['email'];
$company = $_POST['company'];
$phone = $_POST['phone'];
$message = $_POST['message'];
$input_342 = $_POST['input_342'];
$input_2152 = $_POST['input_2152'];
$from = 'From: *****.com';
$to = '*****@gmail.com'; // Email submissions are sent to this email
$subject = 'Customer Submission';
$body = "From: $name'n E-Mail: $email'n Message:'n $message";
if ($_POST['submit']) {
    if (mail ($to, $subject, $body, $from)) { 
        echo '<p>Your message has been sent!</p>';
        } else { 
        echo '<p>Something went wrong, go back and try again!</p>'; 
    }
}

HTML表单：

<form action="/includes/support_form.php" form id="support_form" method="POST">
    <div class="form-group">
        <label>Name</label>
        <input id="name" class="form-control" type="text" name="name" required/>
    </div>
    <div class="form-group">
        <label>Email</label>
        <input id="email" class="form-control" type="email" name="email" required/>
    </div>
    <div class="form-group">
        <label>Company Name</label>
        <input id="company" class="form-control" type="text" name="company" required/>
    </div>
    <div class="form-group">
        <label>Phone Number</label>
        <input id="phone" class="form-control" type="text" name="phone" required/>
    </div>
    <div class="form-group">
        <label>About Your Business</label><textarea id="message" class="form-control" rows="4" cols="50" name="message" type="text" required></textarea>
    </div>
    <div class="form-group">
        <label>Please Contact me by</label>
    </div>
    <div class="radio">
        <label><input type="radio" name="radioSetOne" value="option1" id="input_342"/>Email</label>
    </div>
    <div class="radio">
        <label><input type="radio" name="radioSetOne" value="option2" id="input_2152"/>Phone</label>
    </div>
    <button class="bloc-button btn btn-lg btn-block btn-sea-green" name="submit" type="submit">
        Submit
    </button>
</form>