I wanted to ask for more information and I'll change this bid. Do you expect someone to collect a million emails a day for that niche? If so you will be highly disappointed. It takes time to build a proper mailing list and a million in a day simply isn't done instantly.
If you were thinking about getting just any email, then this is spam, it's illegal and I will not be apart of it. Anyone already offering over a million emails probably didn't take time to research any of them and you will get spam violations.
If you are selling leads, you will need to consider your customers. They don't need a list of leads that have not consented in recieving information. I could collect a million emails in a day, but what if more than half of them for people who live in apartments, live in a different country or even are under age 18? You need to niche out your emails to make them more effective.
I hope you will post a message of what you require with details soon as so someone could make a proper bid on such a project.