/*
 *  Set the Return-Path header to define the envelope sender address to
 *  which bounced messages are delivered.
 *  If you are using Windows, you need to use the smtp_message_class to set
 *  the return-path address.
 */
if (defined("PHP_OS") && strcmp(substr(PHP_OS, 0, 3), "WIN")) {
    $email_message->SetHeader("Return-Path", $error_delivery_address);
}
$email_message->SetEncodedHeader("Subject", $subject);
/*
 *  A message with attached files usually has a text message part
 *  followed by one or more attached file parts.
 */
$text_message = "Hello " . strtok($to_name, " ") . "\n\nThis message forwarding another message that is encapsulated as attachment.\n\nThank you,\n{$from_name}";
$email_message->AddQuotedPrintableTextPart($email_message->WrapText($text_message));
$forwarding_message = array("FileName" => "message.eml", "Name" => "[Fwd: Testing Manuel Lemos' MIME E-mail composing and sending PHP class: HTML message]");
$email_message->AddMessagePart($forwarding_message);
/*
 *  The message is now ready to be assembled and sent.
 *  Notice that most of the functions used before this point may fail due
 *  to programming errors in your script. You may safely ignore any errors
 *  until the message is sent to not bloat your scripts with too much error
 *  checking.
 */
$error = $email_message->Send();
if (strcmp($error, "")) {
    echo "Error: {$error}\n";
} else {
    echo "Message sent to {$to_name}\n";
}