What is the best free software for email marketing?

[Online]

I have 7 million fresh emails. I harvested them automatically from Google, Facebook etc this year.

You can use them;
1. To publicize your product - If you have a product i.e. software, an app or a physical product etc, you can use email list and email marketing to make the world aware.
2. In case of a non-profit organization like a children's home, you can use email list and email marketing to ask for

donations from strangers online.
3. You can also use them as an individual to ask for donations. If you have a good cause, you can use email

list to your advantage and collect good amount of donation money. Well, I've never tried this before.
4. You can also use it to market your website. That's what I mainly use them for.

Check here;
http://www.onlinepesa.com/p/email-list.html