Why you need dedicated smtp server for email marketing
Well if you have purchased lists based on millions of email addresses and you want to send them emails. And because its they are purchased lists so obviously they will have many bad or invalid or inactive email addresses which will cause so many bounces and IP blacklisting. So it means you need a solution which will allow you to send high volume emails to purchased lists at affordable price you cant pay per email delivery in this case it will be out of your budget. So normal smtp or an email marketing account wont be a good solution for you. You must look for a dedicated smtp server from a provider who allow to send bulk emails on daily bases to purchased lists.
Some recommendations for dedicated bulk smtp servers are: