SMS messages are showing the status "Delivered", but they aren't being received by the intended recipients. Whippy is committed to ensuring reliable delivery statuses for messaging services worldwide. However, there are instances where a message may appear as Delivered, even though it hasn't successfully reached the destination mobile device. This document outlines possible causes for these discrepancies and offers troubleshooting tips.
Understanding Delivery Statuses
When Whippy sends an SMS, the status is initially set to Sent.
The status updates to Delivered once the carrier confirms the message has reached the destination.
Possible Causes of Inaccurate Delivery Statuses
Device-Specific Issues: If false positives are occurring to a single device, the problem might lie with that specific mobile device.
Wider Issues: If multiple users are experiencing this issue, it could be due to carrier filtering, local telecom infrastructure problems, or technical limitations of the network.
Troubleshooting Steps for Messages Sent to the US and Canada Using Long Code Numbers
Carrier Filtering: Messages sent as application-to-person (A2P) traffic using standard 10-digit long codes might be blocked by carriers. This is often due to regulatory enforcement.
Error Notifications: Whippy usually receives an error notification from the carrier if a message is blocked or filtered.
Using Short Codes and Toll-Free Numbers: To circumvent carrier filtering, using short codes in the US and Canada can be effective. Toll-free numbers offer a viable alternative, especially for business-related messaging, though they may not be suitable for marketing or promotional content. In Canada, SMS messages from toll-free numbers are subject to the same filtering as long code messages.
Assessing Other Factors
Non-A2P Traffic: If you're not using local long code numbers for A2P traffic, or if you've ruled out the other factors, it's essential to look into device-specific issues or possible network problems.
International Messaging Challenges: When sending messages to countries other than the US and Canada, different challenges may arise. These can include local infrastructure limitations and stricter carrier regulations.
General Tips for Troubleshooting
Check for Multiple Affected Users: This can indicate a broader issue beyond a single device.
Understand Local Regulations: Some countries require pre-registration of alphanumeric sender IDs, which can impact delivery success.
Compliance with Messaging Guidelines: Ensure your messages align with the standard guidelines for SMS messaging in the intended destination country.
By following these steps and considerations, you can better understand and resolve issues related to SMS messages that are marked as Delivered but are not received.