The open-source email platform for products, teams and AI agents

Transactional email API (Resend-compatible) · SMTP relay · Broadcasts and newsletters ·
Business email on your own domain · MCP server for AI agents

Start free on MepMail Cloud · Pricing · Docs · Self-host · Português

What is MepMail?

MepMail puts the two kinds of email a company needs in one place:

• Send: an email API and SMTP relay for transactional email (sign-ups, receipts, password resets, notifications) and marketing broadcasts. It speaks the Resend wire format, so the Resend SDK you already use works by changing the base URL. Delivery runs on Amazon SES.
• Correio (Mail): business email on your own domain. Mailboxes for people and AI agents, a fast webmail, and desktop apps for Windows and Linux.

It is an open-source alternative to Resend, SendGrid, Mailgun and Postmark for sending, and to the Google Workspace or Microsoft 365 inbox for your domain. The whole stack is in this repository under AGPL-3.0.

Cloud or self-hosted

Run it yourself, or let us run it for you. It is the same product, with the same dashboard, API and SDKs.

	MepMail Cloud	Self-hosted
Setup	Sign up and send your first email in minutes	Docker Compose, your own server and AWS account
Amazon SES	Ours: production access, quotas and regions are handled	Yours: leave the SES sandbox and manage quotas
Deliverability	DKIM, SPF, DMARC, bounces, complaints and reputation monitored for you	You wire the SNS events and watch the rates
Business mailboxes (Correio)	Solo, Duo or Equipe plans	Not covered by the self-hosting guide yet
Desktop apps, MCP, updates, backups	Managed	You run upgrades and backups
Support	People who build the product, in English and Portuguese	GitHub issues
Price	Free plan: 100 emails a day, no credit card. Paid plans by card, or Pix in Brazil	Free software; you pay AWS

Don't want to run email infrastructure? Create a free account and you are sending in a few minutes. Correio plans start at US$ 2.90 a month (R$ 14,90 in Brazil), with 7 days free on a card. See pricing.

Features

Send: email API, SMTP and broadcasts

Feature	Notes
Emails API (Resend-compatible)	Send, batch, get and cancel with Resend's request and response shapes.
Idempotency	An Idempotency-Key header de-duplicates retried sends.
SMTP relay	smtp.mepmail.dev:2587 (STARTTLS), authenticated with an API key.
Domains and BYODKIM	Guided DNS verification with live checks; bring your own DKIM key or let SES manage it.
Webhooks (Standard Webhooks)	Signed webhook-* and svix-* headers, per-endpoint events, a delivery log, bring-your-own whsec_ secret.
Contacts and audience	Segments, topics, CSV import and POST /contacts/batch.
Broadcasts	Compose, schedule and send to every contact, a segment or a topic.
Templates	Reusable templates with merge fields and a /templates API.
One-click unsubscribe	RFC 8058 List-Unsubscribe headers plus a hosted unsubscribe page.
Suppression list	Hard bounces and complaints suppressed automatically, managed per address or in bulk.
Metrics and logs	Daily sends with bounce and complaint rates; every API request logged with secrets redacted.
Migrate from Resend	npx @mepmail/cli migrate --from resend copies contacts, segments, topics, templates, webhooks, domains and suppressions. Read-only against Resend.

Correio: business email on your domain

• Mailboxes for people and agents on your domain, with aliases and team plans (Solo with 1 mailbox, Duo with 3, Equipe with 10).
• A smart inbox: People, Notifications and Newsletters in separate tabs, and a new-sender check: approve keeps a sender in the inbox, block sends them to Spam.
• Snooze, pin, follow-up reminders, send later, undo send, quick replies, folders and automatic rules.
• Live updates, 25 MiB attachments, sender logos (BIMI and Gravatar) and message translation.
• Import your existing mail from your old provider over IMAP.
• Desktop apps: Windows on the Microsoft Store and Linux (AppImage, .deb and .rpm).

Built for AI agents

• Official MCP server: hosted at https://api.mepmail.dev/mcp (OAuth) or local with npx -y @mepmail/mcp, for Claude, Cursor, Codex and any MCP client. Agents use the same sending pipeline, limits and logs as your app.
• Agent mailboxes: an agent gets its own address, reads and drafts replies, and a person can approve each send before it goes out.
• n8n: the n8n-nodes-mepmail community node, with a new-mail trigger and mailbox operations.
• Agent discovery: /llms.txt, /.well-known/ai-catalog.json and /auth.md served by the web app.

Send your first email

Create an API key in the dashboard (it starts with ms_), then:

curl -X POST https://api.mepmail.dev/emails \
  -H "Authorization: Bearer ms_..." \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Acme <onboarding@acme.dev>",
    "to": ["delivered@example.com"],
    "subject": "Hello from MepMail",
    "html": "<strong>It works!</strong>"
  }'

Already on Resend? Keep the SDK and point it at MepMail:

import { Resend } from "resend";

const resend = new Resend("ms_...", { baseUrl: "https://api.mepmail.dev" });

await resend.emails.send({
  from: "Acme <onboarding@acme.dev>",
  to: "delivered@example.com",
  subject: "Hello from MepMail",
  html: "<strong>It works!</strong>",
});

On a self-hosted instance, use your own API origin instead of https://api.mepmail.dev. The quickstart and the SDK guide cover every language.

Self-hosting

Requirements: Docker with Compose, and an AWS account with SES access. New SES accounts start in the sandbox and can only send to verified recipients until AWS grants production access.

git clone https://github.com/JE4NVRG/mepmail.git mepmail
cd mepmail
cp .env.example .env

Fill the two required secrets in .env, MASTER_ENCRYPTION_KEY and BETTER_AUTH_SECRET (openssl rand -base64 32 for each), then:

docker compose up --build -d

The dashboard is at http://localhost:3000 and the API at http://localhost:3001.

The supported installation is this local source build (Dockerfile and docker-compose.yml at the root). Images or installers published under other names are not release channels of this project. The AWS setup wizard (pnpm setup:aws), the SES event pipeline, the SMTP relay, TLS, backups and upgrades are in the self-hosting guide and in SELF_HOSTING.md.

Tech stack

TypeScript monorepo (pnpm and Turborepo): Next.js and tRPC for the dashboard, Hono for the public API, a worker for queues and SES events, an SMTP server, PostgreSQL with Drizzle ORM, Better Auth, and Tauri for the desktop app.

Path	What it is
apps/web	Dashboard, Correio webmail and public site
apps/api	Public REST API (Resend-compatible) and hosted MCP
apps/worker	Sending queue, SES events, webhooks and schedules
apps/smtp	SMTP relay and mail protocols
apps/desktop	Correio desktop app (Tauri)
apps/docs	Documentation site (docs.mepmail.dev)
packages/*	Database, billing, core logic, CLI and MCP server

FAQ

Is MepMail free? The software is free and open source (AGPL-3.0). MepMail Cloud has a free plan with 100 emails a day and no credit card; paid plans add volume and Correio mailboxes.

Does it work with the Resend SDK? Yes. Point the SDK's base URL at MepMail and use a MepMail API key; request and response shapes stay the same. See the migration guide for the differences.

Which provider delivers the email? Amazon SES, in your own AWS account when you self-host, or in ours on MepMail Cloud.

Can AI agents send and receive email? Yes: through the MCP server and agent mailboxes, with optional human approval before each send.

Links

• Website: mepmail.dev
• Pricing: mepmail.dev/pricing
• Documentation: docs.mepmail.dev
• API: api.mepmail.dev
• Coming from Resend: mepmail.dev/alternatives/resend
• Integrations: mepmail.dev/integrations
• Support: mepmail.dev/support
• Changelog: CHANGELOG.md

License

The code is licensed under AGPL-3.0. The @mepmail/mcp server, the @mepmail/cli and the n8n node ship under MIT.

MepMail is a fork of an AGPL-3.0 project. The fork notice, upstream attribution and third-party notices are in NOTICE.md. Third-party names, wordmarks and logos belong to their owners and are not licensed under the AGPL.