Stay-in-sight – everything you need for email outbound – open-source An open-source, MIT-licensed email outbound tool called Stay-in-sight has been released, running on Cloudflare Workers with a single D1 database and a passcode for access. The tool queues every email with a send time, enforces per-mailbox daily limits and spacing, supports mailbox warm-up and groups, AI personalization that rewrites each email from recipient data just before sending, AI-categorized replies posted to a webhook, and an MCP endpoint that lets Claude, Cursor or any MCP client import contacts, write templates, preview and schedule sends, and answer replies in-thread. It sends from real Gmail and SES mailboxes with no seats or per-contact pricing, and Cloudflare's free plan works at low volume. Sends that respect your limits Every email is queued with a send time. A per-minute run sends what’s due within each mailbox’s daily limit and spacing, and auto-send spreads a big batch across as many days as it takes. Open source · MIT · runs on Cloudflare Workers Cold outreach, newsletters and drip series from your real Gmail and SES mailboxes. Every contact, email and reply lives in your own database, and an AI agent can run all of it. No seats. No per-contact pricing. Cloudflare’s free plan works at low volume. One Worker, one database, one passcode. Here is what’s inside. New mailboxes start at a few emails a day and climb to their limit on a schedule you set. Several mailboxes send as one. Each email goes from the member with the earliest free slot, and follow-ups stay with the same address. A model rewrites each email for its recipient just before sending, from their contact data and your instructions, and can skip people. Template steps days apart, sent to everyone on a list, including people added later. Add steps any time. Replies are detected every minute or instantly with Gmail push, stripped of quoted history, categorized by AI against your own categories, and posted to your webhook with the whole thread. STOP replies, unsubscribes, hard bounces and complaints are honoured automatically, scoped by mailbox purpose. A template reaches an address once, enforced by the database. Re-send to a growing list and only new people get it. Every email, open, reply, list and series step for one address, across every mailbox, on one page. Send to lists Send to one or more lists, narrowed with the same conditions as the Contacts page, ordered by any field, and capped at the first N. The preview shows who gets it, who’s skipped and why, and the day-by-day plan before anything is queued. AI personalization Turn on AI for a template and write instructions in plain words. Just before each email goes out, a model rewrites it using that person’s data at that moment: their fields, lists, opens and replies. Test it on a real contact first and see the cost per email. Warm-up and mailbox groups Group several mailboxes and send through the group. Each email goes from the member with the earliest free slot by its own limit, spacing and warm-up. Each mailbox has a purpose — cold outreach, newsletter or conversation — that decides how its mail is built. Series Attach lists to a series and everyone on them works through the steps, a set number of days apart. Your app enrolls people by adding them to a list. New steps reach everyone who hasn’t had them, even people who had finished. Replies and webhooks Each human reply is categorized against categories you define, like interested, not now or referral, with your outreach context in the prompt. Auto-replies and bounces are filtered out. Your webhook gets the category, the whole conversation and the metadata you sent with the email. Person timeline Open any address to see every email from any mailbox, sender, list send or series, with opens, replies, list joins, series progress and do-not-send changes, newest first. It works for addresses that aren’t contacts too. Each mailbox declares what it’s for, and the mail it sends is built to match. You don’t need a separate tool for newsletters or for talking to customers. One-to-one emails to people who haven’t heard from you. Bulk mail to people who signed up. Back-and-forth with people who wrote to you. MCP Point Claude, Cursor or any MCP client at your deployment and it can do everything you can in the app: import contacts, write templates, preview a send, schedule it through a group, read the replies and answer them in the thread. claude mcp add --transport http outbound https://