I underpaid a $3 postage fee by 12 cents. What will happen to my package?

I forgot that a stamp is now worth 47 cents instead of 49 cents, so I underpaid in postage. Will the USPS a) return it to me for the remaining 12 cents, b) send it with postage due from the recipient, c) just send it & ignore my goof, or d) make it disappear in a warehouse in Atlanta?

Christian in Jesus2016-11-22T18:40:31Z

They usually will send it back with insufficient postage and you will have to resend it. In small towns the mail carrier will request the postage due from the receiver.

Chris2016-11-21T22:32:15Z

My guess is a)