1

First, you would drop off the letter at the post office or leave it in your mailbox.

2

The USPS carrier collects the mail from your mailbox and takes it to the local post.

3

Mail collected at the post office is then taken to the processing plant.

4

The letter is sent through machines that sort and separate the mail according to size and shape. Envelopes, packages, and boxes are all separated during this process known as the culling operation.

5

The culling operation continues by separating large and small envelopes. A machine arranges the envelopes so all the addresses are facing the same way and a postmark is added to indicate the date and location where the letter was sorted.

6

Next, fluorescent barcodes are added to the back of the letter to identify the letter and address. Addresses that cannot be identified are sent elsewhere for further processing.

7

Barcodes are then added to the front of the letters that indicate a specific delivery address based on specific zip codes.

8

The letter is then sent to a tray containing other letters traveling to that zip code.

9

The tray is sent to the airport to fly to its next destination. Upon landing, post office representatives take the letter to the local processing plant.

10

At the processing plant, letters are scanned through barcode readers, and letters are sorted into specific zip codes.

11

The letters are then sorted into bins for each local carrier and the order in which the letters will be delivered.

12

The postal carrier then drives to the street on their route, delivers mail, and collects any outgoing mail, thereby starting the process all over!