Few questions abt Atomic Mail Sender

[nagarajnow]

Hi Friends
I am New to Email Marketing.. I have few questions abt email marketing..Hope these questions will help for other newbies too..

1. what is email bounce and what happens if this occurs??
2. Why we use proxies for sending emails??
3. We have lakhs of emails here,is it possible to send emails to them if they are not our subscribers??
4. General niche to promote via email marketing to target all age groups..
Here is how I am preparing myself..

I bought Atomic Mail Sender yesterday via blackfriday offer..
I downloaded a list and extract and removed duplicates with Maxprog Email Extrcator..
After that, I used Maxprog Mail verifier and got valid email address now.

Looking for more info for starting out soon..

Thanks in advance..