Render25 Documentation
Render25 is a high-performance transactional email platform built for developers. Send millions of emails with guaranteed deliverability through a global SMTP infrastructure and a simple REST API.
Key features
Sub-second delivery
Our global SMTP network processes emails in under 300ms on average.
Automatic DKIM + SPF
Every domain is automatically signed. SPF records generated on setup.
REST API & SMTP
Use our REST API or plug into any existing SMTP client with zero changes.
Global infrastructure
Distributed across 5 data centers for low-latency delivery worldwide.
Real-time analytics
Track opens, clicks, bounces and complaints with millisecond event logs.
Webhooks
Receive signed delivery events in real-time via webhook payloads.
Quick example
Send a transactional email with a single HTTP request:
curl -X POST https://api.render25.com/v1/email/send \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"from": "[email protected]",
"to": "[email protected]",
"subject": "Welcome to Render25",
"html": "<h1>Welcome.</h1><p>Your account is ready.</p>",
"text": "Welcome. Your account is ready."
}'Compatible with
Official SDKs are available for all major languages and frameworks:
Architecture
Render25 is composed of three distinct layers that work together to ensure reliable, authenticated email delivery at scale:
- API Gateway — A Go-based HTTP gateway that accepts email submission requests, validates payloads, enforces rate limits, and queues messages for delivery.
- SMTP Engine — A custom SMTP server that handles outbound delivery, TLS negotiation, retry logic, bounce processing, and feedback loop integration.
- Analytics Pipeline — A real-time event streaming layer that processes delivery events and exposes them via the dashboard, logs API, and webhooks.
Note