'Smishing': US Postal Service issues warning about text message scam. Here's what to know

Millions of holiday greeting cards and gift packages are making their way through the U.S. Postal Service system in the next few weeks. But scammers are taking advantage, and customers need to be on the defensive.

A new type of scam called "smishing" combines phishing with short messages or texts.

The most common message: one informing the recipient that one of their purported packages can't be delivered until the sender of the text message gets more information from them. Don't click the link -- it's fake.

As a policy, the USPS does not text its customers directly about any problems with packages.

The agency is warning about this. The scam works by sending fake text messages to trick people into sharing information or clicking on a link. In the messages, scammers say there's an issue with delivery or pretend to be a bank, government agency, or a company. They may also ask for account numbers or passwords.

"Those particular types of text messages, those types of correspondences are trying to gain information from customers -- their personal data," said Natashi Garvins of the U.S. Postal Service. She emphasized: "So, again, the Postal Service does not attempt to attain customers' personal information through text messages, emails or phone calls."

But the Post Office does have legitimate ways to track customers' packages -- and it's free. One is by signing up for text tracking.

Another is called Informed Delivery -- where customers receive an email showing their mail and packages as they get scanned. Sign up for the service by visiting the USPS website.

"If you want to get tracking statuses, Informed Delivery is the way to go. Our text messages that you received from Informed Delivery -- they will not ask you for personal information," Garvins said. "They are not going to ask you for your credit card information or anything like that anything that -- anything that is personally identifiable to you."

For customers who did happen to click the link in a nefarious text message or give out any personal information, officials urge reporting it to the U.S. Postal Inspection Service.