Why did my package come back to me?
USPS returns mail it cannot deliver as addressed or forward, routing it home by the return address, per faq.usps.com, checked 2026-07-27. The endorsement stamped on the piece names the specific reason; an Insufficient Address marking, for instance, means the printed address lacked a required element such as the street number, per pe.usps.com.
Did the return trip itself cost anything?
On USPS, usually not: Ground Advantage, Priority Mail and Priority Mail Express pieces that cannot be delivered or forwarded come back to the sender at no additional charge, per DMM 507 at pe.usps.com, checked 2026-07-27. Other carriers set their own return-handling rules, so check the service you used.
Can I get the original postage back?
Not once the label has traveled. The postage was consumed carrying the box out and, in USPS's case, home again. Only an unused label is different: under our terms, those may qualify for a carrier void or postage refund where the carrier permits one, without any promise of it and sometimes slowly.
What is the smart way to resend it?
Confirm the address with the recipient in writing, then buy a fresh label to the corrected destination. When you quote the redo through SMKlog, checkout runs both addresses against carrier address data before taking payment and stops if the destination cannot be matched, which is exactly the failure that caused the first trip.