The postmaster/postmistress's pay is not an attractive one, and they are expected to "diversify" and use other means to get a reasonable income stream. Inevitably some of them try dodgy tactics.
Until quite recently our post office was run by a family as a sideline to their small corner shop. The one most often on the PO counter was mostly all right, but English was not his first language, and his manner could be a little harsh. Every parcel was greeted with a brusque "What's in it?" and he wanted detail, not just a generalisation. Then the PO changed their policies, and the whole shop closed, PO and general store both. A similar corner shop a couple of hundred yards away took over the PO stuff. It was always a rather better shop anyway, and it is a better PO.The proprietor is an Asian man, and it is usually his wife (I think) on counter duty. She is efficient but pleasant with it. I don't know whether it is coincidence, but when he is also in the shop, she wears the scarf of her sari over her head, when he is not she is bareheaded.