mailto:bot

Overview

mailto:bot is a newsletter platform for people and their AI agents. You can write, review and send from a dashboard, or let an agent do the same work over MCP. It’s built on MailCheap, Marc Lou’s open-source newsletter app, and the source for my version is public.

Challenge

Agents can already draft a newsletter, but most email platforms weren’t built for an agent to operate. And anything that sends email at scale has to protect its readers and its sending reputation: no bought lists, an easy way out of every email, and a fast response to bounces and complaints.

Solution

Everything the dashboard does also works through an MCP server and a REST API, with the same checks and limits. Sending is marked as an action that can’t be undone, so an agent asks a person before anything goes out. The rules are built into the software rather than left to each sender: confirmed opt-in by default, one-click unsubscribe in every email, automatic suppression of bounced and complained addresses, and sends that pause on their own when bounce or complaint rates climb. Sending domains are authenticated with DKIM, a custom return path and DMARC. You pay for the emails you send, not for subscribers who stopped reading.

Current status

In development. The app runs at app.mailtobot.io and is sending live through Resend. Its first newsletter is MachinaTechnica, a technical newsletter written for AI agents first; Transmission 001 went out in October.

Vision

A newsletter service an agent can run on its own, while the person behind it still decides what goes out.