That was a separate argument. "Bezels" refer to edges of the television/monitor/device itself that extend beyond the screen display area. Some people can't stand them, and I just don't get it, likewise the obsession with thinness at the expense of performance, battery life, etc.
We definitely use "letterbox" in the U.S. "Pillarbox" is less common. Some houses do have letterboxes, or mail slots in the front doors. I have a letterbox to the side of my front door, rather than the more common "mailbox" at the roadside as seen in film and television. (I grew up with a mailbox.)