+ * @param string $cmd One of the Worker\Delivery constant values
+ * @param integer $item_id 0 if no item is involved (like Delivery::REMOVAL and Delivery::PROFILEUPDATE)
+ * @param string $inbox The URL of the recipient profile
+ * @param integer $uid The ID of the user who triggered this delivery
+ * @param array $receivers The contact IDs related to the inbox URL for contact archival housekeeping
+ * @param int $uri_id URI-ID of item to be transmitted