Cold emails are contextual. There's more ways than the way to do it. But, this is a template which works for me:
It's perfect when you're in the validation stages of a startup. Not only do you get indirect sales by making your target market aware of your startup. You also get useful advice about whether your startup solves a problem or not.
This is the template I used whilst working with a co-working company. We targeted 100 London freelancers. The response rate was 60%. We got a handful of conversions, but the most important thing was the feedback we got about our product :)