Why SMS failed Or Undelivered?

What are the possible reasons why the user does not receive an SMS on his handset?

There can be several reasons why a user might be unable to receive an SMS on their handset, some of the common ones are:

1. Network connectivity issues: The user might not be receiving SMS due to poor network connectivity. They should check if their phone has sufficient network coverage or try restarting their phone to refresh the network connection.
2. SIM card issues: The SIM card might be damaged or not inserted correctly, causing the user to not receive SMS. They should check if their SIM card is properly inserted and try removing and reinserting it.
3. Messaging app issues: The user might be experiencing issues with their messaging app, causing them to not receive SMS. They should check if their messaging app is up to date and try clearing the app’s cache and data.
4. Blocked numbers: The user might have accidentally blocked the number from which they’re expecting the SMS. They should check their phone’s settings to see if the number is blocked.
5. Do Not Disturb (DND) settings: If the user has enabled DND settings, they might not be receiving SMS. They should check if their DND settings are turned on and disable them if necessary.
6. Handset compatibility issues: The user’s handset might not be compatible with the messaging system used by the sender, causing them to not receive SMS. They should check if their handset is compatible with the messaging system and contact their service provider if necessary.
7. SMS Storage Full: Handset/Sim storage full can prevent users from receiving new SMS messages. This is because the phone’s memory is unable to store any more messages, and therefore cannot receive any new ones. To resolve this issue, the user should delete some old messages from their phone’s SMS inbox to create space for new messages. They can do this by opening their SMS inbox, selecting the messages they want to delete, and then deleting them.