How to choose a good SMS platform in Shanghai?

You searched Baidu for a lot of smallpox, all of which your company drank. How dare you say that old customers renew their fees? Whether it is good or not, only customers know best, and no one always changes platforms when they want to be good. I have been dealing with this business for three or four years. I have used cloud movies, Chuanglan, Fetion and Sai Youyun. If you ask me, Sai Youyun is the most convenient. I never say late delivery. Mainly because their customer service is gentle ~