PHP电子邮件脚本在验证后不起作用

关于PHP电子邮件脚本，肯定有成千上万的问题被问到，但我仍然没有找到答案。我查看了php网站，但它也没有真正的帮助。

基本上，我的脚本验证输入并相应地显示错误消息，但当我添加脚本的第二部分来处理电子邮件发送时，页面显示500错误。这是我的密码。电子邮件目前还没有设置为正确的电子邮件，但我知道这不是问题所在。

<?php include('includes/header.php'); 
$yourEmail = "hello@example.com";
$formSubject = "Message recieved from enquiry form";

if( isset( $_POST["submit"])) {
//Validate the data
function validateFormData( $formData ) {
    $formData = trim( stripslashes(htmlspecialchars( $formData )));
    return $formData; 
}

//check to see if inputs are empty
// create variables with form data
// wrap the data with our function
if( !$_POST['name']) {
    $nameError = "Please enter your name <br />";  
} else {
    $name = validateFormData( $_POST["name"]);
}
if( !$_POST['email'] || !preg_match("/^'S+@'S+$/", $email)) {
    $emailError = "Please enter a valid email address <br />";  
} else {
    $email = validateFormData( $_POST["email"]);
}                
if( !$_POST['enquiry']) {
    $enquiryError = "Please enter your enquiry <br />";  
} else {
    $enquiry = validateFormData( $_POST["enquiry"]);
} 

到目前为止，代码工作良好；

//Check to see if submit is set
//Check to make sure errors don't exist
//Send the email
// Redirect user to success.html  

if ( isset( $_POST["submit"]) && (empty($emailError, $nameError, $enquiryError))) {
$to = $yourEmail;
$subject = $formSubject;  
$headers = 'From:'. $name . "'r'n".
    'Reply-To: '. $email . "'r'n".
    'X-Mailer: PHP/' . phpversion();
$body = 
'The person that contacted you was '.$name.'
Email: '.$email.'
URL: '.$url.'
Message: '.$enquiry.''.
mail($yourEmail, $formSubject, $body, $headers);

header("Location: success.html");

}
}
?>

这是HTML表单，考虑到PHP一直工作到某一点并正确显示错误消息，我相信这是可以的。我知道我有PHP_SELF，很多人都说不要使用它，但如果存在错误，我想留在页面上，只在发送电子邮件时重定向。

<form id="contactForm" method="POST" action="<?php echo   htmlspecialchars($_SERVER["PHP_SELF"]);?>">
<label for="name">Name&nbsp;<span class="asterisk">*</span></label> 
 <input type="text" name="name" id="name" value="<?php echo $name;?>"tabindex="1"/>
<span class="error"><?php echo $nameError; ?></span>
<label for="email">Email&nbsp;<span class="asterisk">*</span></label> 
 <input type="email" name="email" id="email" value="<?php echo $email;?>" tabindex="2"/>
  <span class="error"><?php echo $emailError; ?></span>  
  <span class="error"><?php echo $emailValidError; ?></span>  
 <label for="url">Website</label> 
  <input type="url" name="url" id="url" value="<?php echo $url;?>" tabindex="3"/>

 <h3>Tell us about your project&nbsp;</h3><br />
 <textarea name="enquiry" id="enquiry" tabindex="4"><?php echo $enquiry;?></textarea>
   <span class="error"><?php echo $enquiryError; ?></span>  
   <button type="submit" id="submit" name="submit" value="submit" >Submit</button>
 </form>