Send, receive, or relay email from your app

Choose REST for application sends, SMTP for existing mail integrations, or inbound webhooks for replies and email-driven workflows. Postscale connects these paths through verified domains, with primary service data hosted in the EU/EEA.

Need provider-level comparison? Review Postscale as an EU transactional email provider for product teams.

Choose your email workflow

Start with what your application needs to do. Sending from a domain and receiving its mail are separate choices; an outbound integration does not require moving your business inbox.

Send from product code

Use an SDK or POST /v1/send for password resets, receipts, and notifications. Read the production requirements and handle delivery events after the request is accepted.

Set up transactional sending →

Keep an SMTP integration

Configure relay credentials in a framework, CMS, or existing mail client. Use this path when the application already expects an SMTP server.

Review SMTP relay →

Receive replies and attachments

Configure inbound MX, accepting addresses or catch-all, and routing rules. Verify signed webhooks and retrieve stored messages for your workflow.

Build an inbound workflow →

Everything the product needs. Nothing it does not.

A focused API surface with production controls, predictable resources, and the operational visibility to run email confidently.

01

Send transactional email

Trigger password resets, OTPs, magic links, receipts, confirmations, account alerts, and product notifications through REST, SDKs, or SMTP relay.

02

Receive email as webhooks

Point MX records at Postscale and receive parsed inbound messages, headers, bodies, attachments, and sender metadata as signed JSON webhooks.

03

Use SMTP where it fits

Move Rails, Django, Laravel, WordPress, PHP, and legacy systems by swapping SMTP host and credentials instead of rewriting send code.

04

Keep suppressions close to sending

Hard bounces, complaints, unsubscribes, and manual blocks are checked before sending so known-bad recipients do not keep damaging reputation.

05

Add privacy aliases

Create masked addresses for signup flows, marketplaces, feedback tools, and support workflows where users should not expose their real inbox.

06

Monitor deliverability

Track delivered, bounced, deferred, and complained events, import provider suppressions, review DMARC reports, and ramp new senders deliberately.

Start with one request.

The public API uses explicit resources and familiar JSON. Move from a first request to production without changing integration models.

Run this on your server. A test key records a simulated send; a live key requires account approval and a verified sending domain. An accepted request is not proof of delivery. Sending endpoints do not support Idempotency-Key, so do not automatically retry an ambiguous timeout.

Read API docs
Node.js: send through the email API ready
const response = await fetch("https://api.postscale.io/v1/send", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.POSTSCALE_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    from: "Acme <hello@acme.example>",
    to: ["user@example.com"],
    subject: "Confirm your account",
    html_body: "<p>Your verification code is 482193.</p>",
    text_body: "Your verification code is 482193.",
    tags: ["verification"]
  }),
});
const result = await response.json();
if (!response.ok) {
  throw new Error(result.error || "Send request failed");
}
// Keep this ID to correlate later delivery events.
console.log(result.message_id, result.status);

Frequently asked questions

What is an email API?

An email API lets application code submit messages or retrieve received email through HTTP. SDKs wrap those endpoints, webhooks notify your app about events, and SMTP relay is a separate integration option for software that already sends mail.

Can I use the API and SMTP relay together?

Yes. REST sends and SMTP-originated sends share the same verified domains, logs, suppressions, and webhook event pipeline.

Is this for marketing campaigns?

No. Postscale focuses on transactional and product email workflows: verification, password reset, receipts, account alerts, inbound replies, masked aliases, and app notifications.

What counts toward usage?

Outbound usage counts per accepted recipient, including To, Cc, and Bcc. Accepted inbound messages count toward the same monthly quota.

Build the email workflow your product needs.

The free tier includes everything required to evaluate the API. No credit card required.

Create a free account