The email API for sending, inbound, and privacy

Send transactional emails, process inbound messages, protect user privacy with masked addresses. One API.

Get Started Free Log in

Transactional Email API

Send transactional emails with a simple HTTP request. Track delivery, bounces, and complaints in real time.

High deliverability

Real-time webhooks

Template support

Learn more about the Transactional Email API

cURL

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!",
    "html_body": "<h1>Hello World</h1>"
  }'

Complete Email Infrastructure

Everything you need for email

Three products, one platform. Send transactional emails, process inbound messages, and protect user privacy — all through a single API.

Postscale Send

Transactional Email Delivery

Send transactional email with authentication, delivery webhooks, and developer-friendly APIs.

High Deliverability

Authentication, suppression handling, and warming tools that support healthy inbox placement.

Delivery queue

99.98%

healthy

welcome@acme.iodelivered1.2s

invoice@acme.ioqueuedwarmup

reset@acme.iodeferredretrying

receipt@acme.iodelivered0.8s

Bounces

0.12%

Complaints

0.01%

Retries

184

Delivery Event Webhooks

Track delivered, bounced, deferred, and complained events as Postscale processes delivery logs, DSNs, and feedback-loop reports.

POST /v1/send
event: delivered
message_id: msg_8f42

webhook signed

delivered

mx.google.com - 250 2.0.0 OK

deferred

outlook.com - rate limited

suppressed

customer.io - hard bounce

Simple API

Send emails with a single API call. RESTful endpoints, HTTP examples, and comprehensive documentation.

Template Support

Create and manage email templates with dynamic variables. Version control and A/B testing built-in.

Dedicated IPs

Get dedicated IP addresses for full control over your sending reputation. Available on Scale and Enterprise plans.

Automatic Retries

Failed deliveries are retried automatically with exponential backoff, reducing manual recovery work.

Postscale Receive

Inbound Email Processing

Parse incoming emails and deliver them to your application via webhooks. Build support systems, reply detection, and email-powered workflows.

Webhook Delivery

Receive parsed emails as JSON via webhooks, with automatic retries and signature verification.

POST /webhooks/inbound
signature: verified

fromcustomer@example.com

subjectRe: order 4821

attachmentsinvoice.pdf

routesupport.queue

Full Parsing

Extract headers, body (HTML and plain text), attachment metadata, and download links. Clean JSON output ready for your app.

Parsed message

Customer reply detected

Plain text, HTML, headers, and files arrive as normalized JSON.

SPFpass

DKIMaligned

DMARCpass

Actionstore + notify

Attachment Handling

Attachments are stored outside webhook retries and exposed through authenticated Postscale download URLs.

Routing Rules

Filter and route emails by sender, domain, subject, headers, or SPF/DKIM results. Supports regex, AND/OR logic, and actions like forward, drop, or store.

Threading Support

Automatic thread detection using In-Reply-To and References headers. Keep conversations organized.

Spam Filtering

Built-in spam detection with configurable thresholds. Keep your inbox clean and your app secure.

DMARC Reports

Automatic DMARC aggregate report collection and analysis. See who sends email as your domain and track DKIM/SPF alignment rates.

Postscale Shield

Privacy & Masked Emails

Protect user privacy with masked email addresses. Create aliases that forward to real addresses while keeping identities hidden.

Masked Addresses

Generate unique email aliases for each user or service. Real email addresses stay private and protected.

Alias map

user@example.com

shop-9k2@mask.yourapp.com

forwarding

active

trial-p4m@mask.yourapp.com

reply safe

active

promo-1zx@mask.yourapp.com

muted

paused

Reply from Alias

Users can reply from their masked address. Outgoing emails are automatically rewritten to maintain privacy.

Incoming

merchant@example.com

to shop-9k2@mask

shop-9k2@mask

real inbox hidden

Per-User Controls

Enable, disable, or delete aliases individually. Give users full control over their masked addresses.

Custom Domains

Use your own domain for masked addresses. Maintain brand consistency while protecting privacy.

Forwarding Destinations

Forward each alias to one or more destination addresses without exposing the real inbox.

Alias Activity

Track per-alias usage and disable noisy or abused aliases from the dashboard or API.

One platform

Platform Features

Built for developers, designed for scale. Every feature you need to build reliable email infrastructure.

Every email surface in one console

Platform status

Operational

API99.99%

Inbound42ms

Webhooksverified

Audit loglive

Global Infrastructure

EU/EEA-hosted primary service data, with a standard GDPR DPA. Multi-region availability is documented separately.

API-First

RESTful API with comprehensive documentation and HTTP examples for common languages.

Reliable Infrastructure

Redundant systems, active monitoring, and a 99.9% uptime target for production email workloads.

Security First

TLS, webhook signatures, API key controls, and audit logs for operational workflows.

Comparison

Why Postscale?

A single API for transactional email, inbound processing, and privacy-focused aliases.

Feature	Mailgun	SendGrid	SimpleLogin	Postscale
Transactional Email	✓	✓	—	✓
Inbound Webhooks	✓	✓	—	✓
Inbound Rules	✓	—	—	✓
Masked Emails	—	—	✓	✓
Reply from Alias	—	—	✓	✓
Single Unified API	—	—	—	✓
Per-Alias Controls	—	—	✓	✓
DMARC Reports	—	—	—	✓

Built for your stack

Email infrastructure that matches the product you run.

Transactional delivery, inbound workflows, privacy aliases, and compliance paths show up differently by market. These pages map the common implementation shape.