The mobile phone inexplicably received the express pick-up code.

The mobile phone may receive the courier receiving code for the following reasons:

1. Your mobile phone number was leaked or used maliciously, and someone used your mobile phone number to send a courier pick-up code.

2. Your online shopping address is at risk of being leaked and may be used by hackers.

Someone bought you a gift secretly, but didn't tell you.

In order to solve this problem, the following measures can be taken:

1. Contact the courier company and ask for details of the pickup code.

2. Change your mobile phone number to avoid receiving similar messages or phone calls.

3. Installing anti-harassment software on the mobile phone can effectively block short messages and phone calls of strange numbers.

If you receive similar text messages or phone calls, I suggest you call the police.