Tips to send mass emails to purchased lists
Always follow can-spam laws.
Always put unsubscribe link or method prominent in your email header or footer so that people can easily opt out.
Do not send emails daily to purchased lists only send once and then remove the bad ones and send second email after 1 month so that they don’t think you are crazy mailer.
Do not send phishing style emails.
Don’t try to sell try instead try to teach that will help you to keep people in your lists for longer.
If you are using B2C then make sure your IPs are warmed up before sending large quantity emails daily.
Setup feedback Loop with major ISPs like Hotmail, aol, yahoo, Comcast etc…
https://www.massmailservers.net/how-to-send-emails-to-a-purchased-list