code: function CheckOutboxCB(err, results) {
          var result = results[0];  // Query result is alway an array of response even when unique
          self.retry ++; // update retry counter
          // if message is still in queue retry
          self.Debug (6,"CheckOutboxCB Phone=%s Result=%j Retry=%d/%d", smscmd.phone, result, self.retry, smsc.opts.retry);
          if (result !== undefined) {
              // message is still in queue loop one more time
              if (self.retry <= smsc.opts.retry) {
                  setTimeout (function() {CheckOutbox (result.ID);}, smsc.opts.delay);
              } else {
                  // notify appcb that SMS failed and was deleted
                  self.Debug (6,"CheckOutboxCB Fail SqlId=%s SMS=%j", result.ID, smscmd);
                  smsc.DelById (DelByIdCB, result.ID);
                  appcb ({status: -1, smsid: smscmd.id});
  
              }
          } else {
              // le message à été expédié
              self.Debug (6,"CheckOutboxCB OK SMS=%j", smscmd);
              appcb ({status: 1, smsid: smscmd.id});
  
              // if an acknowledgement is asked loop until we get it.
              if (smscmd.ack) {
                  self.retry = 0; // reset retry counter for ack
                  setTimeout (function() {CheckDevAck (smscmd);}, smsc.opts.delay);
              } else {
                    appcb ({status: 0});
              }
          }
      }
docs: this function is call when MySql checked outbox