Pronounciation of "Herb"

My parents received your catalog in the US Mail today. This message was handwritten on the address label.
"It's erb not herb the h is silent"
We are wondering if this is something that your people would have put on it or if somebody did it locally. My parents have pronounced it "(hurb)". What if any is the proper way to pronounce it?

It was not us who wrote that. We pronounce the "h" in "herb" in accordance with the British pronounciation. The American pronounciation mostly follows the French "erb".