MAILSTEIN FOR STARTUPS

Ship email today. Own your sending for good.

One platform for transactional and broadcast email, billed per send — never per contact. Start on the free tier, scale to millions without your bill quietly following your contact list. Your IP, your reputation, your logs — from the first signup email.

Built for the way startups actually move

Wire up sending in an afternoon. Grow into audiences, broadcasts, and dedicated IPs without switching tools or re-platforming.

01 / SHIP FAST

Live in an afternoon

REST API, SMTP, and SDK/CLI. Drop in an API key, send your first verified email, and add SPF, DKIM, and DMARC automatically — no DNS archaeology, no deliverability consultant.

02 / ONE PLATFORM

Transactional + broadcast together

Password resets and receipts run next to your product launches and changelogs. Same contacts, same domains, same analytics — not two products bolted together with two invoices.

03 / OWN IT

Your IP, your reputation

mailstein sends from your own server and dedicated IP via the Postal MTA — not a shared SES pool. Your sender reputation is an asset you build, not something you rent and lose on churn.

The per-contact tax is a growth penalty

PRICING

Pay for sends, not for people

Most platforms meter marketing email by contacts stored — so a list you email once a month costs the same as one you email daily. mailstein bills per send. A 50,000-contact audience you email twice costs the same as anyone else emailing twice.

Free = 50 emails/mo + 1 domain, no card. ~$130/mo at 125K sends, ~$520/mo at 700K sends.
DELIVERABILITY

Premium inboxing, managed for you

Dedicated IPs with automatic, managed warm-up. Bounce and complaint suppression built in so a bad address never burns your reputation twice. The deliverability work a growth-stage team would hire for — handled by the platform.

Warm-up, suppression lists, and DMARC alignment ship on by default — you don't configure them by hand.

Developer-first, all the way down

A real API and a real platform — templates, contacts, campaigns, domains, webhooks, suppressions, analytics — plus an MCP server so your agents can send too.

SEND AN EMAIL

Three lines to your first send

Idiomatic SDKs, typed responses, and webhooks for every delivery, bounce, open, and complaint. Build against a REST API that behaves like the rest of your stack — then reach for SMTP, the CLI, or the MCP server when you need them.

// npm i mailstein await mailstein.emails.send({ from: 'hi@yourstartup.com', to: 'founder@customer.com', subject: 'Welcome aboard', html: '<p>You're in.</p>' })

Where you'll be at 700K sends a month

The choices that feel small at launch compound. Own the infrastructure early and scale never means migrate.

mailsteinTypical SES wrapper
Sends from your own IP + reputationYesShared pool
Transactional + broadcast, one platformYesAdd-on / separate
Billed per send, not per contactYesPer contact for marketing
Message logs live on your serversYesVendor-held
Auto SPF / DKIM / DMARCYesManual
Dedicated IP with managed warm-upYesHigher tier
Free tier, no card50/mo + domainVaries
SDK / CLI / MCP for agentsYesPartial

Send your first email in the next ten minutes

Free tier, no credit card, one domain to start. Own your sending from day one — and keep owning it at scale.

Start free