Convertkit is an emailing marketing platform for podcasters, musicians, marketers, newsletters, and other online creators. There are tools to build an audience with lead generation, an e-commerce function, and easy-to-use automation.
There is a free plan for up to 300 subscribers, then $9 a month for that same 300 subscriber limit. The plan which offers the most value is $25 a month for up to 1,000 subscribers and scales up in price from there.