It depends on several factors. e.g
- How many emails you need to send?
- Is it one time or ongoing?
- What kind of emails you need to send and to what geolocations?
- What is the spam percentage you estimate to receive?
- Is the list your own subscribers or spam list?
If you go for ESPs like aweber, sendgrid etc like everyone else is suggesting you, believe me that is not a solution as no one would allow you to send bulk emails like this. No one wants to burn their own companies. I assume you are willing to send spam and you may need a private solution for it. Get a VPS or Server from any company and get it installed and configured to relay the emails. Use any self-hosted of hosted Email Marketing application like interspire, arpreach or Mumara (our product) to setup your lists and campaigns. The application will push the emails to the MTA for the relay. Server companies are likely more lenient as compared to the shared hosting.
Thank You