Excuse me, what is the reason why SMS is blacklisted?

When short messages are blacklisted, the number of short messages sent exceeds the limit. The restrictions for sending short messages are as follows:

1, and the total number of short messages shall not exceed 500/day;

2. Send no more than 10 short messages containing keywords/day;

3. Send no more than 200 short messages of the same length every day;

4. Send no more than 150 short messages per hour;

5. The maximum number of messages sent on national statutory holidays shall not exceed 2000/day;

6. Conditions for China Mobile and China Unicom to blacklist telecom mobile phone users:

(1) The upper limit of mobile communication is 50 mobile lines per hour;

(2) Unicom 280/ hour;

(3) After the telecom mobile phone number is blacklisted by China Mobile and China Unicom, the system will automatically cancel it after 48 hours.