Jasper is purpose-built for marketing copy and includes dedicated email and newsletter templates that require no technical knowledge, making it the strongest fit here. You fill in a few details about your brand and audience, and it generates polished, on-brand email drafts ready to send. Copy.ai is a close alternative with a similar template-driven approach and a free trial if you want to test before committing. ChatGPT works well when you prefer a conversational back-and-forth to refine your emails without templates. Claude Sonnet is worth considering if you want longer, more nuanced newsletter content with strong tone control.