USPS

WATCH: San Diego's Biggest USPS Processing Plant Offers Holiday Season Tour

The US Postal Service will deliver billions of pieces of mail from Thanksgiving  through Christmas.

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NBC 7’s Dave Summers experienced the holiday rush at San Diego’s biggest mail distribution center.

Moving the mail this time of year through the Margaret L. Sellers Processing and Distribution Center is somewhere between scenes from "Willy Wonka and the Chocolate Factory" and Lucille Ball in Kramer's Kandy Kitchen.

“Dedication, hard work, organization. We plan for this all year,” U.S. Postal Service Operations Support Specialist Melissa Mata said.

Two thousand employees work three shifts in San Diego’s largest processing center.

The USPS increased rates in August. Letters went up three cents, domestic postcards went up four cents and international letters are up 10 cents, to name a few.

It’s had no effect on business so far. Increased online shopping is an added challenge, Mata said.

“We always know there are going to be a lot of people that shop online so we are always preparing for that all year long,” Mata said.

In October, USPS implemented new money-saving service standards, which include more ground deliveries and fewer by air. That means those out-of-town cards and packages could take longer to get to their destination this Christmas. First-class packages and letters, which include Christmas cards, could take 3 to 5 days instead of 2 to 3 according to USPS.

The seasonal post office slogan is "Shop early, ship early." Dec. 18 is the holiday mail deadline.

USPS suggests addressing envelopes and packages with full names and zip codes, and to use sturdy boxes with plenty of packing material and tape.

“If you moved within the last year like many people did during the pandemic, you want to make sure to make that call to the loved one. 'Hey, I don’t know if you are sending me a little something, but let me give you an updated address,'" USPS Spokesperson Maya Lena said.

The next two December Saturdays will be extended “Santa-days” at five San Diego-area Post Offices.

Also, a dozen local post offices will be open to accommodate the holiday rush of customers this Sunday.