Korben receives physical mail to a transparent, flat pneumatic tube in his apartment. When new mail arrives, he hears a whoosh, the envelope drops into place, and the plastic material that the tube is made of becomes edge-lit with the film’s signature orange color.
To retrieve the letter, Korben lifts a hinged side and slides the letter out. The tube hangs at from the ceiling about waist high, to the left of his window desk on the far side of his apartment from the door.
The positioning of the tube is nice as the desk is one place he’s likely to put information received there to use: reading and storing if necessary. Another location might have been near the door, to catch his attention in a physical location that he frequents. But infrequent use is not too much of a problem since the edge lighting should catch his attention.
His attention could be drawn more aggressively to the tube by having the light blink a few times at the arrival of new mail, or when he enters the apartment. Presuming the system knows the importance of a given letters—such as when he is fired from Zorg industries—it could offer an additional audio cue, such as a simple statement of "urgent" using the same voice that announces his allotment of cigarettes in the morning.
Another tiny improvement might be to remove the flap entirely, but adding a grip gap at the edge, on the apartment-facing side of the tube. Presuming this wouldn’t mess with the pneumatic or stability of the letter in place, it would save Korben from having to target and raise the flap. Grabbing mail would just be easier.
Oddly, the edge lighting does not disappear when Korben retrieves letters, which is odd given the slight context-awareness that the rest of the apartment displays. The light should turn off or fade once the letter is removed.