Are you looking for a cheaper alternative to MailChimp? MailPoet is a plugin for sending WordPress newsletters. It helps you send newsletters to multiple lists and manage subscribers. If you very send many emails, it’s likely that you will run into limitations with your SMTP service or your web hosting. But for small quantities of emails, a WordPress plugin like MailPoet will work nicely. MailPoet also offers a plan to send emails for you as a premium service starting at $10/month.
This feature is included in the Formidable Plus plan and higher.