The responses have been non existent. Maybe poor communication on my part.
First of all, what does your program do? How does it help the companies that you have emailed? Does it increase their productivity? Help them to cut cost? Reduce their workload? How is your program compared to those available now? Remember that just because you offer it free doesn't mean you will get great response. You have to give people a reason to stop what they are doing and engage with you.
Also, what is the title of your email? Bear in mind that companies get unsolicited emails all the time. If your title doesn't grab their attention they would probably just block you and delete your email.
Have you tried other ways of testing the water aside from email? You should consider doing some calling and visitation. The response you get from these 2 methods might help you to form a better opinion of the market.