Buttondown

Buttondown strips email down to what writers actually need. It's built and maintained by one developer and uses Markdown for composing, not a visual editor. Your first 100 subscribers are free forever with no time limit, and it costs just a few dollars per month after that. The simplicity extends to analytics (opens and clicks, nothing fancy) and archive management, which pairs well with Substack-style independent publishing.

This fits solopreneurs and writers who prefer working in text and don't need marketing automation features. You won't find workflows or segmentation here, but if you want to send a weekly letter without complexity, Buttondown does exactly that and nothing more.