Wal-Mart's purchase of milk powder showed that customs clearance was abnormal, but no text message was received.

1. Abnormal customs clearance means that there is something wrong with the goods you bought during customs inspection, which may require further inspection or document review. This may result in delayed delivery or temporary shelving of orders.

2. Due to the delay or failure of the logistics system, the SMS notification was delayed or not sent.

3. The mobile phone number you provided is wrong or unavailable, which makes it impossible to receive SMS notifications.