Sendy.co offers a dedicated newsletter platform that is installed directly on a web server. The advantages of Sendy are that it is only a one-time cost (which is very low) and then you only pay for Amazon's mail service (which is also very low). With a dedicated Sendy installation, your company gets an extremely cost-effective solution that can be configured for multiple domains and with different templates and themes. We at JoomlaPro use this solution ourselves to save on all expenses.
Read more about Sendy at https://sendy.co/