Closum's SMS Deliverability Monitoring

How we guarantee the best user experience

Closum has a comprehensive monitoring system to ensure that most SMS deliverability problems are identified and corrected before users realise. This team has a complete set of alerts, tools and automations, ensuring that any problem is detected and addressed quickly.

However, despite all efforts to achieve 100% deliverability, this is not always possible. Most failures are due to legitimate problems related to the recipients' devices, such as network connectivity issues, while to a lesser extent there are also routing problems that can affect message delivery.

Investigation of SMS Deliverability Problems

**When a Closum API user experiences difficulties with SMS delivery and opens a support ticket, Closum's Support team carries out a detailed investigation to identify and resolve the problem. This process includes several troubleshooting steps, including:

• Validation of the message request - We analyse the request to send the message to ensure that it has been correctly submitted.
• Reviewing the relevant error code - We examine the error code provided via the SMS delivery receipt, which may indicate the nature of the problem.
• Comparison with functionalities supported in the country - We check that the message in question complies with the functionalities supported in the destination country.
• Analysing delivery statistics for the route - We investigate the delivery statistics for the specific route used in the message to identify possible faults.
• Reviewing general performance indicators - We monitor the general performance of the destination network to ensure that there are no infrastructure problems.

In some cases, even after following all these steps, it may not be possible to identify the exact reason why a message failed. When this happens, the next step is to open a ticket with the relevant route provider, asking for a more detailed investigation.

Limitations in Investigating Specific Problems

**Although Closum works with multiple route providers, it is not always possible for them to investigate cases where only one specific number is involved. Generally, it is necessary to provide details of several numbers that have experienced problems in the last 48 hours. This helps to distinguish between problems specific to the recipient's device - a common cause of failures - and problems related to the route.

**How to Submit a Support Request **

If you are experiencing problems with SMS delivery and would like our team to investigate, we recommend that you **submit a support request. Whenever possible, please provide as many examples and details as possible so that our team can diagnose and resolve the problem efficiently.Closum is committed to ensuring the best possible experience for its users, and our support team is prepared to deal with any challenge related to SMS delivery.

Updated on: 10/07/2025