Letter sent to the old address, what happens to it?

So.. What happens to a letter sent in the mail that Doesn't have enough postage with No return address?

• I would think it would be illegal for the post office to just throw it out? Does the post office employee have the option of just letting the letter slide and send it forward anyways? ...show more

• Answer:

  If I remember correctly, there's something called a "dead letter bin" where the United States Postal Service puts undeliverable mail. If they can track down who sent the letter, they will ask for postage or if the sender even wants to mail the letter anymore. If not, it just sits there until it is disposed of properly according to federal regulations, however I am not entirely certain what those regulations are.