The reader photographs each envelope as it passes and keeps the image for a week, so a missort can be traced. One item a night is routed by the machine to an address that is not the one written on it, and the image the reader kept shows an envelope with that other address on it, in a different hand, that nobody in the building has seen.
I am the machine's technician, and the image archive is mine to search when a missort is queried.
How the reader works.
Each item passes a camera at speed. The image goes to the recognition software, which finds the address block and reads the postcode, and the item is gated accordingly. The image is stored against the item's sequence number for seven days, and I can pull any item's image by its number and see what the machine saw.
The image is the envelope. That is the whole of the design. There is no other source for the picture.
One item a night is gated to an address that is not on it.
The envelope in the tray is addressed to one place. The machine has gated it to another, and the log shows the postcode it read, and the postcode it read is not on the envelope.
Pull the image for that sequence number and the image shows an envelope addressed to the place the machine sent it. A different address, in a different hand, on what is otherwise the same envelope, the same stamp, the same postmark.
I want to describe this precisely because it is the strangest thing I have to describe. The photograph the machine took of a letter shows a letter that is not the one it photographed.
What has been checked.
The camera, replaced. The software, reinstalled. The image storage, which is a server, and the server's logs, which show the image written at the moment the item passed the camera, at the size and format the camera produces, with no later modification.
The item. The physical envelope, held next to the image on the screen. Same size, same stamp, same crease across the top left corner, same smudge on the flap. A different address, in a hand that is upright and old fashioned, to a street on the other side of the town.
The destination. The item is gated by the image, so it goes to the walk for the street in the image, and the postman for that walk has, on eleven occasions I know of, delivered it to that street, to the number on the image, which is a real house, whose occupant has signed for it, and the envelope in their hand has their address on it.
The envelope changes to match the image by the time it is delivered. I have not been able to say when.
The hand.
I have the images. Two years of them, one a night. The hand is the same hand. I am not a document examiner but I have had a document examiner look at eleven of them, and she said one writer, an older person, trained in a school hand, probably left handed, and asked me why the ink looked like it was still wet in every photograph.
What is done about it.
The item is a correct delivery on the system, because the system's record is the image and the image is right, and the item was delivered to the address in the image, and signed for.
The address on the envelope when it left the sender is the only thing that was wrong, and the sender has never complained, because the sender, on the eleven occasions I have traced, is the same person, at the same address, and has been dead since 2009.
What I do.
I maintain the reader.
The one thing I have changed is that I do not look at the night's image on the screen in the machine hall.
I pull it in the office in the morning, in daylight, with the door open, and the reason is a night when I pulled it at the console beside the machine, at three, with the hall lights on the half setting, and the image came up, the envelope, the old hand, the wet ink, and as I looked at it the address on the screen changed. Not the image. The writing in the image, being written, a letter at a time, in the old hand, while I watched, and it was my address.