如何在PHPMailer上添加特征线？

<?php
require 'PHPMailer/PHPMailerAutoload.php';

$mail = new PHPMailer;

$mail->isSMTP();
$mail->Host = 'smtp.example.com';
$mail->SMTPAuth = true;
$mail->Username = 'your-email@example.com';
$mail->Password = 'your-email-password';
$mail->SMTPSecure = 'tls';
$mail->Port = 587;

$mail->setFrom('from@example.com', 'Your Name');
$mail->addAddress('to@example.com', 'Recipient Name');

$mail->isHTML(true);
$mail->Subject = 'Test Email';
$mail->Body = '<h1>This is the email content</h1><hr><p>Some more text...</p>';

if(!$mail->send()) {
    echo 'Message could not be sent.';
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Message has been sent.';
}
?>