What are the SMS platforms for SMS promotion in Beijing? Ask for recommendation

There are many SMS companies in Beijing, but few people want to choose a reliable SMS platform. When choosing, we should start with the following points: registration period? Registered capital? Is the document complete? Is it the main resource? Is the channel stable? Is the price reasonable? What is the arrival rate and speed? Do you support free test SMS? Do you support triple play? Do you support free interface docking? Can I view the delivery status report in real time? These are all things that need attention, I hope I can help you!