USPS Set To Deliver An Absurd Amount Of Mail This Holiday Season

Rudolph can only guide the sleigh to so many houses for package deliveries before the little guy gets tuckered out.

Thankfully, the United States Postal Service has access to cargo planes to pick up the slack. And when you're dealing with numbers that end in "billion," that's a good thing.

This holiday season, the USPS expects to deliver a total of an estimated 15 billion cards, letters and packages, around 612 million of which were processed on Monday alone, spokeswoman Sarah Ninivaggi told The Huffington Post.

Monday, Dec. 14 was "peak day," aka the Postal Service's busiest mailing day of the year. Last year, the USPS processed around 640 million cards, letters and packages on peak day, Ninivaggi said.

While the decline follows an overall drop in the amount of First-Class mail being sent, the volume of packages is actually on the rise, she said. Some 600 million packages will be delivered this year between Thanksgiving and New Year's Eve, 10.5 percent more than the same period last year.

Here's a pro tip: If you are unable -- or unwilling -- to visit a post office to drop off a package, you can schedule a pickup here, for free . You can also have empty Priority Mail Flat Rate boxes delivered to you , also for free.

Anxious to make sure your package arrives by Christmas? Here's a cheat sheet of domestic mail-by dates to ensure delivery by Dec. 24. (For international dates, click here .)

Dec. 15 -- Standard Post
Ground service for less-than-urgent deliveries and oversized packages. 

Dec. 19 -- First-Class Mail
Service for standard-sized, single-piece envelopes and small packages weighing up to 13 ounces with delivery in 3 business days or less.

Dec. 21 -- Priority Mail
Domestic service in 1, 2, or 3 business days based on where your package starts and where it’s being sent; variety of Flat Rate options.

Dec. 23 -- Priority Mail Express
Fastest domestic service, guaranteed overnight scheduled delivery to most locations.

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