电子邮件联系方式不工作

我想知道是否有人能看到我在这里做错了什么。我的html看起来像这样

<form action="process.php" method="post">
    <fieldset>
        <div id="inputLeft">
            <p>
                <label for="name">Full Name</label>
                <input class="validate[required,custom[onlyLetter],length[0,100]]" name="name" type="text" id="name" value="">
            </p>
            <p>
                <label for="email">Email Address</label>
                <input class="validate[required,custom[email],length[0,100]]" name="email" type="text" id="email" value="">
            </p>
            <p>
                <label for="subject">Subject</label>
                <input class="validate[required,length[5,600]" name="subject" type="text" id="subject" value="">
            </p>
        </div>
        <div id="inputRight">
            <p>
                <label for="country">Country</label>
                <input name="country" type="text" id="country" value="">
            </p>
            <p>
                <label for="phone">Phone Number</label>
                <input name="Phone" type="text" id="phone" value="">
            </p>
            <p>
                <label for="url">Website</label>
                <input name="url" type="text" id="url" value="">
            </p>
        </div>
        <p>
            <label for="message">Message</label>
        <textarea name="message" cols="120" rows="8" id="message"></textarea>
        </p>
    </fieldset>

和这样的PHP

<?php
   # recipient
   $recipient = 'sean@seankonig.co.za'
   # subject
   $subject = $_Post['subject'];
   # headers
   $headers = "Website enquiry <>'r'n";
   # message
   $message =  "Name : {$_POST['name']}'n";
   $message .= "Email : {$_POST['email']}'n";
   $message .= "Subject : {$_POST['subject']}'n";
   $message .= "Message : {$_POST['message']}'n";
   if( mail($recipient, $subject, $message, $headers) ) echo "Mail Sent";
   else echo "Mail Could Not Be Send";
?>

测试时，它说邮件已经发送，但没有发送。你可以看一下然后告诉我吗?