BATON ROUGE- The deadline to pay first-class prices for Christmas present deliveries passed Tuesday. However, people willing to pay extra still have a few days left.

Wednesday is the last day letters and packages can be mailed with the United States Postal Service with its Priority Mail service. And Friday is the absolute last day to get presents to their destination by Christmas morning, but customers will pay even more with Priority Mail Express.

Once the packages are in the mail, postal workers will do the rest. Automated distribution centers sort and send mail with ease but customers do have to write down the correct address.

"The machines read the zip codes," said Justa Smith a postal worker in Baton Rouge. "If the zip code is wrong it's going to the wrong part of the country."

Tuesday marked the busiest mailing day for the Post Office nationwide with 611 million pieces of mail processed. Thursday will be the busiest day for deliveries with 30 million packages arriving on door steps.