Cold email outreach,
without the busywork.

Import your contacts, verify your domain, and send marketing emails that reach the inbox — all from one simple dashboard.

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Everything you need to send

From your first import to a clean sender reputation — mailer123 handles the whole pipeline.

Import in seconds

Upload a CSV or Excel file — contacts are validated and de-duplicated automatically. A group column even sorts them into the right groups on the way in.

Verify your own domain

Add a domain and get the exact DKIM, SPF, and DMARC records to publish. Once verified, send from any address on it.

Campaigns that land

Send through our authenticated infrastructure. Rotate subjects and From addresses round-robin across recipients.

One inbox for replies

Set a single Reply-To per campaign so every response lands in one place, no matter which address it was sent from.

Protect your reputation

Bounces and complaints are auto-suppressed, and risky addresses are flagged before you send — keeping your sender score healthy.

Track every send

Per-recipient delivery, opens, and clicks, with a full history of every campaign and a 30-day activity overview.

Warm up new domains

Ramp a fresh domain gradually with automatic daily increases and bounce-rate guards that pause sending before your reputation takes a hit.

Personalize every message

Merge tags like {{name}} and your own custom fields fill in per recipient — with fallbacks — across subjects, bodies, and reusable templates.

From zero to inbox

Up and running in three steps

No sales call, no setup fee — most teams send their first campaign the same afternoon.

Import your contacts

Drop in a spreadsheet or add people manually, then organize them into groups.

Verify your domain

Publish the DNS records we generate. We poll the status until you’re verified for sending.

Send & track

Compose from a template, send now or schedule, and watch delivery in real time.

Built for developers

Send from your code, or let an AI do it

A typed SDK, a clean REST API, and an MCP server — so mailer123 fits a Next.js route handler, a backend job, or your AI assistant.

Node SDK

npm install mailer123 and send your first email in three lines. Typed, dependency-free, and ready for Next.js route handlers, server actions, and edge runtimes.

REST API

A clean /api/v1 API for emails, contacts, campaigns, and templates — authenticated with a workspace key, rate-limited, with a consistent error envelope.

MCP for AI agents

Connect Claude, ChatGPT, or Cursor to the MCP server and let an assistant send mail, manage your audience, and run campaigns in plain language.

>_ send.ts

import { Mailer123 } from 'mailer123';

const mailer = new Mailer123();

await mailer.emails.send({
  from: 'you@yourdomain.com',
  to: 'customer@example.com',
  subject: 'Welcome aboard',
  html: '<p>Glad you're here, {{name|there}}!</p>',
});

Read the docs API reference MCP for AI agents

Plans that scale with you

Start free, upgrade when you grow. Every plan includes your own verified domains, campaigns, and tracking.

Free

Everything you need to start sending.

$0/mo

3 sending domains
250 emails / day
5,000 emails / month
30 days data retention

Get started

Pro

Scale

Coming soon

High-volume sending for established teams.

Custom

100 sending domains
10,000 emails / day
100k emails / month
90 days data retention