Don't do it. It's spam and you don't like it when it happens to you. Be part of the solution, not the problem.
You'll get a huge portion of your emails in the spam folder, because no reputable email provider will let you send that many emails to a purchased list.
You'll get very very few opens, because most are in the spam, and those that aren't nobody knows who you are. It's like a cold phone call, a fax or a piece of junk mail. Nobody wants it.
You'll get a huge amount of complaints and bounces. A list with that many emails isn't going to be very good. Even if you spent the money and got it scraped yourself, there will be a large proportion of dead mailboxes.
Nobody on that list wants to buy from you. They don't know you and they don't trust you. So you have to write an amazing email to overcome that. Like the best one you've ever written.
It's just not a good idea. Go back to the drawing board. If you want to send email, build a list yourself of people who are interested in your company and what you offer. Reach out to them by being helpful and offering them something - they'll like you for it.
