How can the issue of "No recipient addresses found in header" in the PHP script be resolved?

To resolve the issue of "No recipient addresses found in header" in a PHP script, you need to ensure that the `mail()` function includes valid recipient email addresses in the header. Make sure to provide at least one recipient email address in the `to` parameter of the `mail()` function.

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

mail($to, $subject, $message, $headers);