Graciously shoot down an idea with this gentle rejection letter for businesses.
Free to download and print.
Dear {Name},
Thanks so much for thinking of us with your idea for {product/action/etc.}. We appreciate your creativity and your willingness to share your expertise with us.
Unfortunately, this idea is not a good match for our needs. Of course, that doesn't mean it's not a good idea! In fact, I'd suggest that you {approach other party/do it yourself/revise concept/etc.}.
Best of luck to you. Please feel free to reach out with further concepts that you'd like to share. If you'd like to give me a quick call, I can offer a little more feedback. My number is {number}.
Sincerely,
{Name}