Transactional Email API

Transactional email that arrives

Send the emails your product depends on — password resets, receipts, order confirmations, notifications — via REST API or SMTP relay. EU-hosted, GDPR-native, with webhooks for every delivery event.

Get started free See sending docs

REST API and SMTP relay

Use whichever fits your stack. Both endpoints share the same authentication, rate limits, logs, and webhooks — no pick-one-and-regret-it.

DKIM and DMARC handled

Add two CNAMEs and we rotate keys for you. SPF, DKIM alignment, and DMARC-friendly From: addresses are set up correctly from day one.

Real-time webhooks

Delivered, opened, clicked, bounced, complained — each event fires an HMAC-signed webhook within seconds. Retries with exponential backoff.

Templates and merge fields

Store reusable templates with variable substitution. Version them, A/B test subject lines, localize by recipient — without shipping code.

Suppression list included

Complaints, hard bounces, and unsubscribes are managed automatically. Hitting a suppressed address fails fast instead of damaging reputation.

EU-hosted, GDPR-native

All processing, storage, and delivery stay in the EU. Standard DPA, no US data transfer, no Schrems II paperwork for EU controllers.

cURL — send a transactional email

curl -X POST https://api.postscale.io/v1/send \
  -H "Authorization: Bearer ps_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "from": "hello@yourapp.com",
    "to": ["user@example.com"],
    "subject": "Welcome to Acme!",
    "html_body": "<h1>Hello World</h1>",
    "text_body": "Hello World"
  }'

# Response
{
  "message_id": "msg_01HY...",
  "status": "queued",
  "remaining_today": 99999
}

Frequently asked questions

REST or SMTP — which should I use?

REST if you control the code sending email; SMTP if you're migrating from an existing system that already speaks SMTP (Django, Rails, WordPress, legacy PHP). Both use the same rate limits, logs, and webhooks — no functional difference.

How good is the deliverability?

We run dedicated IPs with established reputation, enforce DKIM + DMARC alignment, auto-suppress complaints, and participate in feedback loops with the major mailbox providers. Inbox placement is a property of your sender behavior too; we give you the tools but won't rescue spam.

What does it cost?

Free tier includes a working volume for evaluation. Paid plans start at €9/mo. See /pricing for per-tier message limits.

Can I send from my own domain?

Yes — add two CNAMEs and a TXT record, and you send as you@yourdomain.com with proper SPF/DKIM/DMARC alignment. Most setups take five minutes.

Ready to build?

Free tier includes everything you need to evaluate. No credit card required.

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