My Momma taught me that if you don't have anything nice to say, say nothing at all.

I tend to ignore the offers(must have been caught in the spam filter)

There is one local flipper that always sends a stupid low offer and says he will pick it up tomorrow.
That being said, I had an ad on CR recently and added the phrase "please don't waste my time with low ball offers - you know who you are"

Felt a bit like a prick for doing so, but it worked.