Blue's Clues & Joe's 3D Scavenger Hunt (Windows game 2004)
It's a shareware (trial) 3D game based on an educational tv series called Blue's Clues aired by Nickelodeon (Nick JR).
The main character called Joe must find the object which the letterbox (mailbox, postbox) requires getting around.
By the way, It has a fatal error (This application cannot run with an active debugger in memory. Please unload the debugger and restart the application.), so I ran it on Windows 7.
