Probably not normal. I post ads on Racing Junk regularly and only a few are questionable. If the specific item you post is not mentioned in the inquiry, I just ignore it. If the person really wants it they will call you if they don't get a response back to their written inquiry. Any contact that feels the least bit fishy, just ignore. Do not respond. There are enough legit buyers out there to sell to without giving out any info you don't feel comfortable with putting out there for a scammer to use against you.
I have sold over 100 items on Racing Junk and it is still the best place I have found to buy and sell on.