Transactional email service for product teams
Send the emails your product depends on: password resets, OTPs, magic links, receipts, order confirmations, billing notices, security alerts, and product notifications via REST API or SMTP relay.
Need sending, inbound, SMTP, and privacy aliases together? Start with the Email API commercial hub.
SDKs, REST API, and SMTP relay
Use the official Node.js, Python, Ruby, or PHP SDKs, call the REST API directly, or keep an SMTP integration. Each path shares the same authentication, rate limits, logs, and webhooks.
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, bounced, deferred, and complained events fire HMAC-signed webhooks as Postscale processes delivery logs, DSNs, and feedback-loop reports. Retries use exponential backoff.
Templates and merge fields
Store reusable templates with variable substitution. Version them, A/B test subject lines, and 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/EEA-hosted primary service data
Primary production service data is hosted in the EU/EEA. Limited network, device, and operational metadata may be processed by infrastructure providers under appropriate transfer safeguards.
import { Postscale } from "@postscale/postscale";
const postscale = new Postscale(process.env.POSTSCALE_API_KEY);
const { data, error } = await postscale.emails.send({
from: "hello@yourapp.com",
to: ["user@example.com"],
subject: "Welcome to Acme!",
html_body: "<h1>Hello World</h1>",
text_body: "Hello World",
});
if (error) {
throw new Error(error.message);
}
console.log(data?.message_id);Frequently asked questions
What is a transactional email service?
A transactional email service sends user-triggered and application-triggered messages such as password resets, verification codes, receipts, order confirmations, invoices, account alerts, and product notifications.
REST or SMTP: which should I use?
Use an SDK or REST if you control the code sending email; use SMTP if you're migrating from an existing system that already speaks SMTP, such as Django, Rails, WordPress, legacy PHP, or a hosted app. All paths use the same rate limits, logs, and webhooks.
How good is the deliverability?
We run authenticated sending domains, enforce DKIM and DMARC alignment, auto-suppress complaints, and participate in feedback loops with major mailbox providers. Inbox placement also depends on your sender behavior, recipient quality, and ramp discipline.
What does it cost?
Free tier includes a working shared send and receive volume for evaluation. Paid plans start at EUR 9/mo. Outbound usage is counted per accepted recipient, including To, Cc, and Bcc.
Can I send from my own domain?
Yes. Add DNS records for domain verification, DKIM, SPF, and return-path alignment, then send as your own domain with proper authentication.
Further reading
Email API for developers
The broader product email API surface: transactional sending, SMTP relay, inbound webhooks, suppressions, and masked aliases.
SMTP relay for transactional email
Move existing apps, frameworks, CMSs, and legacy systems by swapping SMTP host and credentials.
SPF, DKIM, and DMARC: the 2026 setup guide
Required reading if you're configuring a sending domain this year. Gmail and Yahoo's bulk-sender rules apply.
EU-hosted email APIs: what GDPR actually requires
The DPA, subprocessor, and transfer-safeguard questions you should ask every vendor before signing.
The EU-hosted SendGrid alternative
What changes, and what does not, when you move transactional sending from SendGrid to Postscale.
Amazon SES alternative
When SES is the right raw primitive, and when a focused email API saves engineering time.
Ready to build?
Free tier includes everything you need to evaluate. No credit card required.
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