Cold Emails for Client Pitching

I recently started my own Freelance SEO services website. I could've registered on Upwork or freelancer but I thought it's better to have a site with the services I provide. Now it's been live in the last week and we know that SEO takes time to get organic traffic and form fills.

I was thinking of cold emailing the potential clients, those who are ranking beyond the 3rd-4th Page.

So question over here is should I use a GMAIL or BUSINESS EMAIL to pitch the clients?

I am totally new to cold emailing. Can someone please guide me over here?