If there is any day Santa Claus needs help delivering presents this year, it's Monday, Dec. 16.

It will be the busiest mailing day of the year at the United States Postal Service (USPS), as officials expect 6 million people across the country to stop by their local branch on one day.

At Madison's east side post office, when it comes to mailing and shipping, window clerk Mike King has the routine down. 

First he extends a greeting, before he asks the important questions.

"Anything in there fragile, liquid or perishable or potentially hazardous," King asked a customer delivering a few packages on Friday.

Once the mailing is set, King went over how to track the items and said goodbye.

The USPS expects to process more than 600 million pieces of mail that day.  Madison alone expects to see its volume of mail triple.

On Friday, customer relations coordinator Goldie Bristol described the peak mailing day as chaos but exciting at the same time.

"People are so excited to be doing what they're doing," said Bristol.

Bristol added to prepare for the big day USPS hired additional help and workers plan to clock in extra hours.

"It isn't just getting the packages in, it's transporting them and adding additional transportation, adding flights, putting mail on extra planes, things like that.  It's a lot of things folks don't think about when they think of dropping their letter in the mailbox," explained Bristol.

For King, who has worked with USPS for 23 years, the secret to working the busiest mailing day is to maintain holiday cheer and take one customer at a time.

His advice to people planning to mail anything Monday--just make sure the packages are ready and they will take care of the rest.

UPS will also be extra busy Monday.  According to its website, it expects to pick up 34 million packages Dec. 16.