Here you get US based E-Mail OptIn's. Count should be like 5million. Since I am taking and taking I wanted also share with you what I found on the web by surfing. Those leads are in the
business sector.
+1 Reputition would be great
You asked what to do with 5 millions leads in another thread and now you are giving to us these 5 millions? Really?
This sounds very hot, I still could not download everything. But I'll give you REP for this.
Hope it be hot.
EDIT: you asked for a software to deliver these emails in mass. The recommended software for this kind of task is the well known:
http://www.phplist.com . Just install it on the server, set it up and schedule when you want the emails to be delivered. All this will be done by pressing a button. Plus, you will need to create some email template(s) to ease your work much better. There are many tutorials on the Internet on how to do it.