I need 7 millions USA business emails in csv format

I need 7 millions USA email list in already made csv format and that will be easy to upload directly on my email subscriber list. please this should be a valid emails and also the email should be clean, and easy to upload to my subscriber list because I have less experience on csv formatting.. but if the database is not clean,,, the seller should give me instruction on how to upload it easily on my list....

I will appreciate if the seller can give me site in which I can use in sending newsletter and email list upload