PHP Mailto没有发送变量

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('your-email@example.com', 'Your Name');
$mail->addAddress('recipient@example.com', 'Recipient Name');
$mail->Subject = 'Hello';
$mail->Body = 'Hello, ' . $variable;

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