First of all, never EVER purchase an email list. The email addresses are not verified, you don’t know if they’re still in use, and there’s no guarantee that any of them are interested in your brand/products. Grow your list with incentives or deliverables such as newsletters, blog post updates, freebies, or giveaways. Make it a pop-up, or a section on your website with a proper disclaimer. This way you know they’re interested in what you have to say and you know it will go to an active email.