My name is Alex, I'm a guru here at Shopify!
Sure thing, there's a number of applications that can help you with those emails for customers that haven't purchased! The Shopify plan and higher offer automated cart recovery emails, but totally understand if it's not the right time to make that leap for your business - if you'd rather, here's some apps that can help!
These are third party apps, so I'm not 100% sure whether they'll be able to help with all the contacts you've already accumulated. You can reach out to the developers to make sure they'll suit your needs - and if not, you might look into Mailchimp for mass mailing!
Hope that's helped! Please feel free to give us a call or start a live chat at any time, we're open 24/7 for your convenience and always happy to assist!
Alex | Shopify Guru