https://developers.weixin.qq.com/doc/offiaccount/Message_Management/Batch_Sends_and_Originality_Checks.html

通过 预览接口 推送消息给 已经取消关注的用户， 接口并未返回异常状态，与关注时成功推送的结果一样.

{“errcode”:0,“errmsg”:“preview success”}