How does mail delivery work? KSAT Explains

A viewer asked, so we found out!

This KSAT Explains was prompted by a question from a viewer named Natalie.

She asked, “The postal system. How does mail get from where you put it in the mailbox to its destination? How does it get sorted? How does it read bad handwriting on envelopes? How long is a mailman’s route?’

Natalie sent us the question through a section of our website where we ask what you want Explained.

So, we got to work.

Main USPS processing plant

All mail sent to or from the South Texas region is processed through the United States Postal Service processing plant at 10410 Perrin Beitel Road.

The service region covers from the U.S.-Mexico border to the south and just shy of San Marcos to the north.

“We are running on average about 10 million pieces of mail per day as far as letters,” USPS Executive Plant Manager Kimberly Calderon said.

During processing, each piece of mail is labeled with a barcode that contains info about its intended destination.

“Each one of these machines here are capable of running 11 letters per second,” Calderon said.

“The machine is looking for a barcode very specifically on the front side to see if that information is available, so that we know how to sort the machine to the appropriate bin,” she added.

Letters are sorted by destination. For example, all mail staying within San Antonio goes to one bin while mail going to Houston goes to another.

“We also put a special barcode on the backside of a mail piece,” Calderon said. “And that helps us to make sure that the information on the front side of the mail piece and the backside of the mail piece is exactly the same.”

Calderon says mail sent and received within San Antonio should take two days to arrive.

If the letter or package is traveling out of San Antonio, it should leave the processing plant the morning after it arrives there.

“Tomorrow morning, early,” Calderon said. “That will make sure that if it goes out on a plane, it’s on that designated plane. If it goes out on the truck, it’ll be on that truck.”

A thousand scheduled trucks

There are 1,001 scheduled USPS trucks on the road seven days a week. Sometimes there are more if there is a higher volume of mail.

Michael Oliver has driven one of those trucks for 22 years.

“Every day I just come to work and, go to the stations, and I pick up mail at the post office, and I bring it back in so it can get us sorted,” Oliver said.

He spends roughly four hours on the road daily.

“Basically, I do like the, Southeast and the East side,” Oliver said. “That’s my area.”

Oliver hits the road at 11:35 a.m. to pick up early collections of mail gathered from the blue USPS collection boxes.

“We work hard. We work hard to get the mail out on time,” he said.

“Believe it or not, we start counting at minute one,” Calderon said. “It’s one minute late. It’s two minutes late.”

The busiest time of day at the 200,000 square-foot facility is 7 p.m.

That’s when roughly 350 to 400 trucks arrive at the plant to deliver the bulk of mail collections.

“This is just the start of a really busy time,” Calderon said.

Mail is sorted by shape first

“We want all the letters together, all the flats together, all the packages together,” Calderon said.

After its sorted by shape, each piece of mail is “cancelled.”

“That means we’re going to cancel the stamp,” Calderon said. “We’re going to read every piece of information on that particular mail piece. And then we’re going to start tracking it throughout our systems.”

Cancelling a piece of mail signifies that it has been received at the plant and the next phase of delivery has begun.

It’s alive

Did you know living creatures can be shipped via USPS?

When KSAT toured the facility, our cameras captures crates of bees and boxes of baby chicks.

“You should see when we get the live fish through here,” Calderon said.

“These are going to be handled, just like we would handle anything else,” she added. “With the exception, we’re going to make sure that no other mail pieces are obstructing any of the air holes that you see.”

What if the address is wrong?

Sometimes senders get the address wrong. Or their handwriting is hard to read.

So we asked, does a human have to interfere with the machines in that case?

“Not necessarily. Most mail is resolved just by looking in our directory system to see where that mail piece actually needs to go. And the machine does that. In most cases, yes,” Calderon said.

If mail is being delivered in San Antonio, its shipped out to a local post office after being processed.

Mail is grouped together and sent to the post office that services the route on which each piece of mail is supposed to go.

Hello, Postman Pete

Pete Velasquez has been a mail carrier for 26 years and delivering on the same route for the last 22 years.

Part of his route includes the KSAT studios.

He makes deliveries in the same order every day.

“Every single day,” he said.

When mail arrives from the processing plant to a local post office, mail carriers must sort that mail based on the order in which it will be delivered on their route.

“This is what we call our case area. This is how we do sortation of mail,” Velasquez said. “It means you’re putting it into these little dividers. These dividers are specifically for each specific address within the route itself.”

Velasquez makes 1,500 daily deliveries. He gets started between 8 a.m. and 9 a.m. and ends deliveries anywhere from 5 p.m. to 6:30 p.m.

Deliveries tend to take longer earlier in the week, he said.

Velasquez has not only seen lots of growth in the downtown area over the years, he’s gotten to know many of the people who live and work on his route.

“I’ve gone to plenty graduations. I’ve seen some folks go to their quinceaneras or seeing them during Fiesta when we’re out there delivering, waving at them,” he said.

Velasquez loads his mail truck based on the order in which pieces will be delivered on his route.

A scanner tells mail carriers during which hour each package should be delivered along their route.

“The item would tell you it’s in section three,” Velasquez said. “The back of the truck is numbered one, three and five for this section and two, four and six on that side. So that item would be loaded in the section three side... It’s within the third hour of delivery.”

He’s out of his truck about every 30 seconds.

“Rain, snow, sleet, Covid and solar eclipse, as well! You got to deliver it,” Velasquez said.

Find more KSAT Explains episodes on here

About the Authors

Myra Arthur is passionate about San Antonio and sharing its stories. She graduated high school in the Alamo City and always wanted to anchor and report in her hometown. Myra anchors KSAT News at 6:00 p.m. and hosts and reports for the streaming show, KSAT Explains. She joined KSAT in 2012 after anchoring and reporting in Waco and Corpus Christi.

Valerie Gomez is lead video editor and graphic artist for KSAT Explains. She began her career in 2014 and has been with KSAT since 2017. She helped create KSAT’s first digital-only newscast in 2018, and her work on KSAT Explains and various specials have earned her a Gracie Award from the Alliance for Women in Media and multiple Emmy nominations.

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