What should I do if I can't receive some short messages because I sent some short messages?

I have worked in related companies, and I can tell you for sure that there are several situations in this situation; 1, it's a problem with the other card (there may be other reasons why it can't be used normally, such as downtime, no charge, etc. , and does not rule out whether the information storage of the other party's mobile phone has reached the maximum). In this case, no matter which customer service phone you call, I will tell you (first, I will judge whether you are a customer of the operator). I'll check your card for you. If there is no problem, they will advise you to consult the operator of the other card 2. Finally, it is suggested to check whether the other party's card is damaged, sometimes it is ok; 3. It may be that the other party's mobile phone or some other means have blocked some numbers, which may lead to the possibility of not receiving them; 4. It is possible that the other party blocked some keywords; 5. Sometimes there will be some delay in SMS. Generally speaking, the maximum delay will not exceed 72 hours.