Assist me with Bulk Marketing - I need to clean up an email list of 1 million registries

I have a 1 million email list. But it was achieved by a online campaing where people only had to insert their emails and notthing else, and there was no autethication if it was a valid email or not. I need someone that can clean it up and give me back only emails that are valid. I will have to review the job before payment. i need confirmation that the email list clean up was really effective. Thank you