Starting up…
Most tools do one or the other. Mail does both — run a campaign to thousands, write a single high-touch response, and receive every reply in an inbox you already have open. On your server, with your Resend key.
Sending is the easy half. What breaks later is the duplicate send after a retry, the bounce nobody recorded, and the reply that went to an address nobody reads.
Resend forwards inbound mail to your instance over a signed webhook. Your server verifies it, throws away duplicate deliveries, and stores the message.
Threads group by message ID, so replies land under the conversation they belong to. New mail appears over Server-Sent Events — no polling, no refresh. The conversation is highlighted where it lands, so you can see which one is new without reading the timestamps.
With the tab closed, a web push notification reaches the device instead: the sender, the subject and the opening line, arriving the moment the webhook commits and filled in with a preview once the body is fetched. With the tab open, a short sound — one cue for mail arriving, another for a send that failed — which you can turn off per browser.
The same editor writes a single message with Cc and Bcc or a personalized send to four thousand people. Attachments travel with the message; images dropped into the body are uploaded and linked.
Drafts save as you type. Close the tab mid-sentence and the sentence is still there.
A campaign materialises one row per recipient before sending, claimed in batches with an UPDATE … RETURNING lock so workers never collide.
Every message carries an idempotency key, so the provider discards a duplicate even if replayed.
CSV import reports rejected rows and reasons — malformed addresses, missing columns, or existing duplicates.
Addresses are normalized at the boundary, so a suppression on Bob@Example.com still catches bob@example.com.
Hard bounces and spam complaints are recorded automatically from webhooks and checked on every send path.
A bounce cannot be removed manually. Respecting server bounce responses is vital to domain reputation.
A setup wizard collects credentials with step-by-step instructions and live test validation before saving.
Updates stream via SSE, so server reloads or environment additions advance setup seamlessly.
Four styled HTML templates — Simple, Announcement, Newsletter and Plain — built with React Email, plus any HTML template you upload yourself. Pick one while composing a message or a campaign, or set an instance-wide default in Settings so every send starts there.
Your logo and brand colour flow into whichever design is chosen, so a template switch never means re-uploading assets.
A pnpm monorepo: a Next.js app and eight modular packages behind it — database, email, jobs, auth, redis, shared contracts, theme, and PWA layer.
Clone it, open the setup wizard in your browser, and paste your Resend key. Nothing phones home, and the data stays in your database.
Every message carries an idempotency key, so a retried batch cannot send twice.
3 rows were not imported:
Bounces and complaints are recorded automatically and cannot be removed by hand — the receiving server’s verdict is not a preference.
Pick one per message, or set an instance-wide default in Settings — your logo and brand colour flow into whichever is chosen.