how to get the users which have sent me messages??

Hi,

how can i get the users which have sent me messages? (distinct)

Following code provides me all messages i got. How can I adapt it?


$messages = elgg_get_entities_from_metadata(array(
    'type' => 'object',
    'subtype' => 'messages',
    'metadata_name' => 'toId',
    'metadata_value' => $page_owner->guid,
    'owner_guid' => $page_owner->guid,
    'limit' => $limit,
    'offset' => $offset,
));

THX, stoffal