How can I use the information collected from one form and send them a return email

I would like to "blast email" a group of respondents to my form. How do I collect then use their email.

Thanks

Can you please explain your question in more detail? I'm not sure I understand what you're referring to properly. 

Do you want to be able to view your submissions and take the email address out of that? If so, this guide will help you get to your submissions data:

How to View Form Submissions

Thank you.