PHP电子邮件表单不发送电子邮件

Question

我在转到“谢谢”页面的网页上有一个表单。

但是，它没有向我的电子邮件帐户发送应有的信息。

这是HTML代码：

 <form action="form.php" method="post" name="contact form">

                    <input class="text-input"  type="text" name='name' placeholder="Name*" required ><br>

                    <div class="twenty-five-h-divider"></div>

                    <input class="text-input" type="text" name='email' placeholder="Email*" required><br>

                     <div class="twenty-five-h-divider"></div>

                    <textarea id="subject" name="subject" placeholder="Message*" class="text-input form-field pointer"></textarea>

                    <div class="twenty-five-h-divider"></div>
                   <p> <input type="checkbox" name="spambot2" value="Yes" id="spambot2" required> <label for="spambot2">Yes I am human</label></p>

                    <div class="twenty-five-h-divider"></div>

                    <input type="submit" class="submit-button pointer" value="Send Message" name='submit'>

                </form>

这是PHP表单代码：

<?php
session_start();
if(!isset($_POST['submit']))
{
    //This page should not be accessed directly. Please use the form.
    echo "Error, please return to last page.";
}
$name = $_POST['name'];
$email = $_POST['email'];
$spambot = $_POST['spambot2'];
$subject = $_POST['subject'];

if ($spambot != 'Yes') {
    $spambot = 'No';
}

//Validate first
if($spambot == 'No')
{
    echo "Please go back and check the 'I'm not a Spambot' box.";
    exit;
}

//Validate first
if(empty($name)||empty($email)) 
{
    echo "Name, email and phone number are mandatory.";
    exit;
}

if(IsInjected($visitor_email))
{
    echo "Bad email value!";
    exit;
}


$email_from = 'person@gmail.com';//<== update the email address
$email_subject = "Adam Brind Contact";
$email_body = 

    "Name: $name\n \n".

    "Email: $email\n \n".

    "Message: $subject\n \n".

$to = "person@gmail.com";//<== update the email address
$headers = "From: $email_from \r\n";
$headers .= "Reply-To: $visitor_email \r\n";
//Send the email!
mail($to,$email_subject,$email_body,$headers);
//done. redirect to thank-you page.
header('Location: thankyou.php');


// Function to validate against any email injection attempts
function IsInjected($str)
{
  $injections = array('(\n+)',
              '(\r+)',
              '(\t+)',
              '(%0A+)',
              '(%0D+)',
              '(%08+)',
              '(%09+)'
              );
  $inject = join('|', $injections);
  $inject = "/$inject/i";
  if(preg_match($inject,$str))
    {
    return true;
  }
  else
    {
    return false;
  }
}

?>

以下是到实时网页的链接：adambrind.com

我需要修复表格的帮助，以便它将信息发送到电子邮件中。