private PushResultMessage push(@Nonnull Notification notification, boolean ignoreFrequency) {
IPreferences prefs;
final String unknownChannel = notification.getParams().get(INotifyService.NOTIFY_UNKNOWN);
if (unknownChannel != null) {
prefs = new Preferences().setUserId(notification.getUserId());
} else {
prefs = _preferencesDAO.getPreferences(notification.getUserId());
}
if (prefs == null) {