使用WxMpMassSendResult根据openId群发消息，用户收不到消息！请问是什么原因？

WxMpInMemoryConfigStorage wxStorage =getWxStorage();
WxMpService wxMpService = new WxMpServiceImpl();
wxMpService.setWxMpConfigStorage(wxStorage);
WxMpMassOpenIdsMessage massMessage = new WxMpMassOpenIdsMessage();
massMessage.setMsgType(WxConsts.MassMsgType.TEXT);
massMessage.setContent(content);
massMessage.setToUsers(openIds);
WxMpMassSendResult sendResult = wxMpService.getMassMessageService().massOpenIdsMessageSend(massMessage);

提示{"errorCode":"0","errorMsg":"send job submission success","msgId":"3147483683","msgDataId":"2247483684"}
发送成功，但是微信上未收到发送的信息，有时候一个微信号能收到！