For years there’s been a mailbox in front of the Vision Services for the Blind apartment building on 23rd Street. And with good reason. Dozens and dozens of blind and disabled people live here. They need a mailbox close by. But a few weeks ago we heard from Flo Fox, a well-known photographer who lives here. She told us that suddenly, the mailbox was removed. She couldn’t get a straight answer when she inquired at the main Post Office. So she contacted me for help.