Your comment is utterly wrong and obviously shows you dont know what your talking about. I send 20K emails a day using hotmail accounts and they only fail after I start sending, have never gotten blacklisted before sending while using residential proxies.Instead use mail ru cause hotmail will get blacklisted even before you start no matter you use residential proxies or premium proxies and coming to sending part you can use leaf mailer or others which are open source. Or simply buy SMTP to send emails to all 20M contacts.
Good luck
No one will allow you to do that unless you host your own SMTP server.
you can use mailer or you can just write your own python code to get the job done.
it's possible but there is a chance of your mails ending up in the spam if you are not doing it properly
