What is the default frequency limit for sending SMS messages?

To ensure business and channel security and minimize potential financial losses caused by malicious calls of SMS APIs, the default frequency limit for sending SMS messages is as detailed below:

• For SMS messages with the same content, a maximum of one such message can be sent to the same mobile number within 30 seconds.
• A maximum of 10 messages can be sent to the same mobile number on a calendar day.

Organizational users can log in to the SMS Console to set or modify the corresponding frequency limit policy. For detailed directions, please see Setting Sending Frequency Limit.
Note: individual users have no permission to modify the frequency limit. To use this feature, change "Individual Identity" to "Organizational Identity".

How do I add alarm contacts?

For detailed directions, please see Configuring Alarm Contact.

How do I prevent SMS bombing?

SMS bombing is an attack where the attacker exploits web client or server vulnerabilities to send a large number of verification code SMS messages to many irrelevant mobile numbers in a short period of time (such as within one day) by using malicious programs or tools. Such attacks harass mobile phone users severely.
Below is an actual case encountered by a customer (in normal cases, dozens of SMS messages are delivered every day, while tens of thousands of messages are delivered every day during the bombing):

SMS bombing not only makes the SMS channel unavailable due to high numbers of complaints made by harassed users, but also causes serious financial losses for the business. Therefore, you need to take preventive measures.
As SMS bombing is usually initiated by servers, you are recommended to take the following measures for prevention:

• Add CAPTCHA. Tencent Cloud provides the Tianyu anti-cheating feature.
• Limit the number of requests for a single IP.
• Limit the number of messages sent to a single mobile number. You can set the sending frequency limit and configure alarm contacts.
• Set an excessive messaging reminder.
• Log in to the SMS Console to view the specific statistics and check the SMS message delivery conditions regularly (such as once a day). If there is any exception, fix it timely. In case of emergency, you can deactivate the SMS service in the console.

What are the differences between sending Mainland China/Global SMS messages?

As required by carriers, Mainland China SMS messages must carry an SMS signature; for global SMS messages, SMS signature is optional, and you can choose whether to carry a signature as needed.

• Before sending a Mainland China SMS message, you should first create a signature and a body template, which need to be reviewed and approved.
• Before sending a global SMS message, you should first create a body template, which needs to be reviewed and approved. If you want to carry a signature in the messages, you should create it and have it reviewed and approved; otherwise, you do not need to create a signature.

How do I query the sending records for a single mobile number?

You can log in to the SMS Console, click the name of the target application to enter the application details page, and select a query method as needed:

• Mainland China SMS: select Statistical Analysis > Mainland China SMS > SMS Record to query the records as shown below:
  
• Global SMS: select Statistical Analysis > Global SMS > SMS Record to query the records.

How do I create and view an application (SDK AppID)?

An SDK AppID is used to identify an application. Each SMS application has a unique SDK AppID, which will be automatically generated by the system after the application is added.
You can log in to the SMS Console, select Application Management > Application List, and click the name of the target application to enter the application details page and view its SDK AppID.

How do I add testing and alarming mobile numbers to the frequency limit whitelist?

To exclude testing mobile numbers from the frequency limit, please consult SMS Helper.

How do I know whether a specified mobile number has received an SMS message?

You can log in to the SMS Console, click the name of the target application to enter the application details page, and select a record query or export method as needed:

• Mainland China SMS: select Statistical Analysis > Mainland China SMS > SMS Record to query or export the records in the specified period of time.
• Global SMS: select Statistical Analysis > Global SMS > SMS Record to query or export the records in the specified period of time.

Is there a limit on the number of Global SMS messages?

Under a single Tencent Cloud account, up to 1,000 Global SMS messages can be sent per day. To adjust the limit, please consult SMS Helper.