3 Stores are packed right now with shoppers -- but your local post office is also busy too! So if you're looking to send out holiday cards or gifts -- like this -- there may be long lines. Today, the U-S postal service processed the most mail in a single day. And, across the country -- more than 600- million pieces of mail will be processed today alone. Channel 4's Ashley Mitchem says it's more than just the post office that's busy-- Fed-Ex and U-P-S stores are also seeing an increase in traffic. 3 3 10-1542-471:05-1:101:37- 1:41INTRO: 15:50 The U-P-S store downtown is packed full of customers-- all trying to send out their gifts in time for Christmas Day.NAT POP 12:51 is this anything breakable? No ..Monday is the busiest for the postal service ...Thursday is the busiest for FedEx and UPS...In all, nearly 15-billion pieces of mail is delivered between Thanksgiving and New Year's Eve.FedEx is expected to move more than 20 million packages...UPS employees are working around the clock to deliver about 300 packages per second.We spoke with Terry Wilkins- at the U-P-S store downtown about workers' busy schedules.Terry Wilkins, UPS Store Owner 03:44 Especially early in the morning and then around lunch time it can get a little crazy...One sender says it gets so busy and expensive she may skip out next year... Michell Long, Gift Sender 02:46 I am going to gift cards from now on ... When I'm mailing long distance because the cost of shipping was about $40 and I know you can add that to the cost of the gift card and they can get what they want.Every few minutes a new customer walked in the store downtown...and it wasn't even peak time...Wilkins says to send a gift on time without paying the big fees of overnighting a package ..you need to do it as soon as possible.05:03 Probably after tomorrow I would not send it ground outside the southern states at allDepending on where you need to ship an item, the Christmas cutoff dates for UPS run December 20th-24th.Here are some important deadlines to know U-S-P-S:) Friday, Dec. 20: Deadline for sending first- class mail Saturday, Dec. 21: Deadline for priority mail Monday, Dec. 23: Deadline for sending priority mail expressBut some senders say if you miss the deadline it's better late than never... Stephanie Smith, Gift Sender 11:56 no she knows if it gets there it gets there. Whenever!Local post offices, UPS and FedEx locations all have different hours of operation so check online before you try to send or ship-- some are even open Christmas Eve others are not... AM C4 TLS.