Authorities say that Stacey Champion, 39, tried to mail the 4-month-old dog from Minneapolis, to Atlanta, in a package with no food, water or air holes, The Star Tribune reported.
If postal workers hadn't found the animal, it would have died, officials say.
according to The Daily Telegraph. "It would have been kind of traumatizing to get a dead puppy."
Postal workers became suspicious when they saw the package move on its own and thought they heard it panting. They rescued the black poodle-schnauzer mix, whom they have christened "Guess."
The dog "was so happy to get out," said Thompson Ojoyeyi, a postal worker. "We gave him water and he drank so fast."
It is legal to send certain animals, such as bees and some cold-blooded animals, through the mail. But it is not legal to send animals such as cats and dogs.
Champion has been charged with animal cruelty. Authorities say she hasn't said why she thought she could send a dog through the mail -- or why she didn't tell postal workers about the box's contents.
"She just wanted her money back," Ojoyeyi said, according to The Daily Telegraph.
Guess was taken to the city's animal control facility. It's not clear whether Champion will try to keep the animal, but it seems likely Guess will be put up for adoption.
Everyone who has worked on the case is hoping that he will find a good home.
"He's cute as a bug's ear," Dodge said, according to a local Fox affiliate.