$email_message->AddPart($text_part);
/* Iterate personalization for each recipient. */
for ($recipient = 0; $recipient < count($to); $recipient++) {
    /* Personalize the recipient address. */
    $to_address = $to[$recipient]["address"];
    $to_name = $to[$recipient]["name"];
    $email_message->SetEncodedEmailHeader("To", $to_address, $to_name);
    /* Do we really need to personalize the message body?
     * If not, let the class reuse the message body defined for the first recipient above.
     */
    if (!$email_message->cache_body) {
        /* Create a personalized body part. */
        $message = "Hello " . strtok($to_name, " ") . ",\n\nThis message is just to let you know that Manuel Lemos' e-mail sending class is working as expected for sending personalized messages.\n\nThank you,\n{$from_name}";
        $email_message->CreateQuotedPrintableTextPart($email_message->WrapText($message), "", $recipient_text_part);
        /* Make the personalized replace the initially empty part */
        $email_message->ReplacePart($text_part, $recipient_text_part);
    }
    /* Send the message checking for eventually acumulated errors */
    $error = $email_message->Send();
    if (strlen($error)) {
        break;
    }
}
/* When you are done with bulk mailing call the SetBulkMail function
 * again passing 0 to tell the all deliveries were done.
 */
$email_message->SetBulkMail(0);
if (strlen($error)) {
    echo "Error: {$error}\n";
}
echo "Done!\n";