Unitpost
Transactional email

Email your users actually receive

Receipts, password resets, verification codes, alerts — the mail your product depends on. Send it over a clean REST API or SMTP, with idempotency, signed webhooks, and deliverability built in.

Developer-first

Send with your favorite stack

A simple, predictable interface so you start sending in minutes. Fire a single API call — with idempotency keys so a retry never double-sends — or point any SMTP client at the same pipeline.

  • One call to send

    REST or SMTP, same pipeline, same guarantees.

  • Idempotent by design

    An Idempotency-Key dedupes retries — never a double receipt or reset link.

  • Scoped keys

    Capability-based keys mean a service can send and nothing more.

Send an email
import { Unitpost } from "unitpost";

const unitpost = new Unitpost(process.env.UNITPOST_API_KEY);

await unitpost.emails.send({
  from: "you@acme.com",
  to: "user@example.com",
  subject: "Your receipt from Acme",
  html: "<p>Thanks for your order!</p>",
});

Drop-in SMTP

Already have an SMTP setup? Point it here.

Swap your host, username, and password and keep your existing mail code. Same deliverability, tracking, and webhooks as the API — no rewrite required.

  • STARTTLS & implicit TLS

    Ports 587 and 465, with 2587/2465 aliases if your host blocks them.

  • API key as password

    Authenticate with a scoped emails:send key — rotate or revoke anytime.

SMTP relay
Hostsmtp.unitpost.com
Usernameunitpostfixed
PasswordYour API keyemails:send
Port 587STARTTLSsubmission
Port 465Implicit TLSSSL

Observability

Complete visibility of every message

Every email generates a series of events — delivered, opened, clicked, bounced, complained. Inspect each one, watch the rates roll up, or stream them to your own endpoint.

Password resetDelivered
To
ada@example.com
From
you@acme.com
Sent
4m ago
Tracking
Opens · Clicks
  1. Delivered2s
  2. Opened1m
  3. Clicked · acme.com/reset1m

Built for reliability

Everything a transactional stream needs

The pieces that matter when an email is part of a user flow — speed, idempotency, and deliverability that keeps mail out of spam.

Deliverability built in

DKIM, SPF alignment, and DMARC with continuous re-verification keep transactional mail in the inbox.

Templates by id

Author in the visual builder or React components, then reference them by id on every send with variables.

Batch & scheduled

Send up to 100 messages in one call and schedule for later, with the option to cancel before send.

Per-message tracking

Every message is traceable in the dashboard and over the API — know exactly what happened to that reset email.

Automatic suppression

Hard bounces and complaints suppress the recipient automatically, protecting your reputation.

Rate-limited & safe

Per-workspace limits keep sending healthy; scoped keys keep blast radius small.

Extendable

Do more than sending

One SDK, every resource. Click through real examples — transactional sends, marketing campaigns, templates, webhooks, and scoped API keys — all programmatic, all through the same keys.

Send an email
import { Unitpost } from "unitpost";

const unitpost = new Unitpost(process.env.UNITPOST_API_KEY);

await unitpost.emails.send({
  from: "you@acme.com",
  to: "user@example.com",
  subject: "Your receipt from Acme",
  html: "<p>Thanks for your order!</p>",
});

Quick integration

Connect easily with any service

Add Unitpost to the tools you already use — or point any SMTP-capable framework at the relay.

Flexible

Ready for every use case

Whether it's a welcome email or a critical alert, there's a reason to reach for transactional mail.

Password resets & magic links

Time-sensitive auth mail that lands instantly — idempotency means a retry never sends two links.

Receipts & invoices

Order confirmations and billing emails, rendered from templates and traceable per message.

Verification codes

OTP and email verification with the deliverability to reach the inbox, not spam.

Welcome & onboarding

Personalized first-touch mail fired the moment a user signs up.

Alerts & notifications

System alerts, mentions, and activity digests fired from your backend or SMTP.

Trial & renewal reminders

Let users know when a trial is ending or it's time to upgrade — on schedule.

User invitations

Invite teammates to a workspace with tracked, reliably delivered links.

Legal & policy updates

Terms and privacy changes to your whole user base, with per-message proof of delivery.

Start free

Send your first email in minutes

$0/ mo

  • Generous free tier — no credit card
  • Pristine shared IPs
  • Automatic suppression list
  • Signed webhooks & tracking