/**
 * do frequently backup
 *
 * @param null
 * @return null
 */
function incoming_mail_handle_on_frequently()
{
    set_time_limit(0);
    require_once INCOMING_MAIL_MODULE_PATH . '/models/IncomingMailImporter.class.php';
    require_once ANGIE_PATH . '/classes/UTF8Converter/init.php';
    require_once ANGIE_PATH . '/classes/mailboxmanager/init.php';
    $mailboxes = IncomingMailboxes::findAllActive();
    IncomingMailImporter::importEmails($mailboxes, 20);
}