Ask HN: Question about prospecting via email

I have been trying to find early adopters for my CRM lite tool (www.petworkslabs.com). I have been talking to local businesses, but mostly I have been cold emailing businesses and following up. After about 300 emails, my email has started getting marked as spam. I worry that if enough people mark my email address as spam, then my email account would become un-usable. I looked at email campaign tools like mailchimp etc, but their terms of usage states that I need permission from the email recipient before sending anything out. So question to the community, how do you keep prospecting via email, without getting your account marked as spam?

FWIW - I am personalizing each email and I am not sending out bulk emails.