Maybe an online clearinghouse for responding to non-customer emails.
No, what I meant was that if it took 50 emails to help get the item working properly for the customer, then probably there are a LOT of frustrated customers out there... so it might be a good idea to have tutorials or video demos or something else on how to use the product.
In the end, I guess the response to a non-customer depends on a business owner's personality.
Or their ability to create a marketing opportunity out of it.
One other thought is that I try to take customer emails and turn them into blog posts or other content for my site as well, or use it as inspiration for facebook / other social media. Also, it does pay to go through them because you will learn what products THAT YOU DON'T CURRENTLY CARRY are popular.