code: function SendToCB (err, result) {
          // check if sms was sent from output table
          self.Debug (7,"SendToCB SMS=%j result=%j err=%j", smscmd, result, err);
          if (err) {
              self.Debug (1, "Insert in MySql outbox refused %s", err);
              appcb ({status: -1, id: smscmd.id, error: err});
          } else {
              setTimeout (function() {CheckOutbox (result.insertId);}, smsc.opts.delay);
          }
      }
docs: this function is called when MySql inserted SMS in outbox