A possible customer from NY contacted me with a request-for-quotation. I replied back with an estimate in hours and money, defining several elements of the project.

Before that, we exchanged some emails and though we don't know each other personally, we have some "community" ties with one another.

The thing is that I am from Spain and in my opinion even if you are not interested you should reply back. I would like to know if this behavior is culturally appropriate in New York or, if in the business world this has some other meaning.