What happens if a parcel is sent with no zip code on it?

Question

I had a parcel sent to me via Priority Mail that has not arrived. I think that maybe there was no zip code on it. What would happen to such a parcel assuming they did in fact NOT write a zip code on the address?

Dead letter office? Held at their PO? Returned to sender? Something else?

Thanks.

Answer 1

They usually send it to the address. Takes longer. Sometimes if they are not busy they write it on the item for you.