Why would the post office send my package back to the seller?

Question

He sent it in a little bubbled envelope .When my address is current

Answer 1

perhaps you used a po box--you need a mailing adress.

Answer 2

Check your local sorting office. they normally get sent there. :)

Answer 3

If it's from eBay it's likely he fudged the postage if he did it in paypal... they're cracking down on it and sending items back or forward with postage due....