在PHP邮件中更改mailed-by标头

<?php
$to = "recipient@example.com";
$subject = "Test email";
$message = "This is a test email.";
$headers = "From: sender@example.com\r\n";
$headers .= "Reply-To: sender@example.com\r\n";
$headers .= "X-Mailer: PHP/" . phpversion();
$headers .= "mailed-by: myserver.example.com\r\n";

if(mail($to, $subject, $message, $headers)) {
    echo "Email sent successfully!";
} else {
    echo "Error sending email.";
}
?>