LetterBucket is a newsletter platform for creators, founders, and media teams that unifies email sending, web publishing on your custom domain, subscriber management, automations, and analytics while ensuring you fully own your audience and revenue; it also includes a built‑in AI writing assistant (LLMs) to help draft, edit, summarize, and optimize subject lines and copy so you can produce polished issues faster and boost engagement without platform lock‑in or revenue share.