What many IT guys do not realize is that
website is absolutely not needed for businesses from "yellow pages" nowadays.
Just in my circles I know quite a few small offline business owners who do not have a website, and simply do their promotion through Facebook, or only have a Google my business account. And they are successful in what they do. Or they do not have any online presence at all...
What's more, still way too many people send emails like you.
I get dozens of offers for website redesign monthly, let alone for SEO, to different emails accounts on different websites combined. Sometimes I open one out of curiosity, but typically I simply delete it altogether.
My idea for you:
Change your approach completely. Instead of sending hundreds of emails to people who do not know you, go out and network. Visit the places, buy something, come repeatedly, try to make a connection.
Once they know you tell them what you do, and just then try to pitch them for making a website.
You can easily convert 1/5 leads in this way if not more. Build your name and reputation in local community, and they will even recommend you further. What's more, you will actually get to know local people and places, which is a nice benefit of such an approach