Missie Kittok swung open the hatch of her white U.S. Postal Service truck, grabbed two boxes and delivered them swiftly into the mailroom of a tony condo complex on the edge of downtown Minneapolis.

It was the first of nearly 90 stops Kittok would make, schlepping boxes and packages, tall and skinny, small and thick, into mailboxes, mail rooms and apartment entry ways. That she was delivering on a Sunday — and on a Christmas Eve Sunday to boot — brought cheer, and surprise, to those on the receiving end.

"These are really all for us?" asked Carter Casmaer, an emergency room doctor who came down the stairs of his second-floor apartment to greet Kittok and collect seven packages, a few of them sizable.

"I really have no idea what's inside," he said. "I'm going to have to talk to my wife."

John Hussey, who lives in a senior high rise in Elliot Park, was pleased to see a mail carrier on Christmas Eve. But, he clarified, "Every day, I'm happy to see 'em."

In fact, the Postal Service has been delivering packages on Sundays regularly for about a year, including on Christmas, said spokeswoman Darla Swanson.

The shift no doubt reflects a need for the 242-year-old service to respond to the realities of the modern consumer, vigorously engaged with online purchasing and not a big fan of delayed gratification.

USPS also is delivering Priority Mail Express packages on Christmas Day. Between Thanksgiving and New Year's Eve, the post office will deliver an estimated 850 million packages and more than 15 billion pieces of mail, Swanson said.

Kittok, 35, will be celebrating Christmas Day with her family. She said working on the eve isn't so bad.

"It's a short [work] day," she said. "And you're in the car most of the time."

Kittok joined the Postal Service about 15 months ago. She's a CCA, or city carrier assistant. "It's like an intern," she said.

Before that, Kittok worked for a bookstore for many years and as a receptionist. In the latter job, she was getting tired of sitting. She noticed the mail carrier who came in every day. "That looks kind of fun," she thought. "It must be nice being out in the sunshine.

"Of course, that was during summer."

She liked the thought of being independent. And it's hard to beat the physical fitness aspect of carrying the mail. Her shoulders are getting stronger, as are her legs.

Kittok pulls out her blue bejeweled phone case and opens it. On Saturday, just before Christmas Eve, she walked 32,000 steps.

Her downtown Minneapolis coverage area is dense, mostly apartments, duplexes and some upscale condos in the shadow of U.S. Bank Stadium.

"It's quicker when you're driving," she said. "But you have to find your way a little bit more."

Walking or driving, she layers for warmth. She wears an aviator hat and thick gloves with open fingers to allow her agility in pulling out packages. "This coat is so warm that, whenever I'm inside, I start sweating," she said.

"Good morning and thank you!" a front desk guard calls out to her. "Merry Christmas!" shouts another. One customer made her Christmas cookies. "That was really nice," she said.

"Sometimes they're waiting at the door when they see me drive up," Kittok said. Once in a while, she'll get an apology:

"Sorry about that thing I ordered."

But among her favorite responses, for those looking out their windows on Christmas Day and seeing one of her co-workers:

"Oh, you're working today? Thanks so much."

Gail Rosenblum • 612-673-7350