It sounds like you're asking for a review of a product called — likely a downloadable file or a tool claiming to provide one million email addresses in a text file.
Before writing a full review, I must give a : Buying or using pre-compiled email lists (especially of that size) almost always violates anti-spam laws (like CAN-SPAM, GDPR, CASL) and the terms of service of most email marketing platforms (Mailchimp, ConvertKit, ActiveCampaign, etc.). It leads to low engagement, high spam complaints, and potential legal fines.