Hello,
There is two ways to clean the lists, 1) To Ping and Check MX Records, Contact the ISP for Valid email ID confirmation other way is to clean the email list by sending email to all email ID through that you clean out most of bounces, Spam Traps, Sender Rejection and Filterization by the ISP. For option 1 I will charge 100$ and for option 2 I will charge 300$. I hope you will consider. Thanks
Regards