I get requests for free images all the time. It is time consuming and a little rude to just say "Can I use you photos for free". Usually I answer "No". If the initial email had all the information, I would be far more willing to at least consider the request. Here is a great start at what you should include in the initial request.
"...My contact page is a little scary. The message is basically, “Don’t email me if you haven’t done your own research, and don’t ask for free pictures if you don’t ask the right way.”..."