Email & SMTP Transport

GNS provides dedicated email delivery backed by a self-hosted Postal SMTP relay cluster with persistent connection pooling, TLS encryption, and deliverability protection.

1. Default Shared Sender Handle

By default, every application receives a dedicated email address on the shared IITDeveloper domain:

{application_slug}@iitdeveloper.com

For example, an application named "Acme Billing" with slug acme-billing dispatches from:

"Acme Billing" <acme-billing@iitdeveloper.com>

2. Dispatching an Email

curl -X POST "https://api.gns.iitdeveloper.com/api/v1/notifications" \
-H "Authorization: Bearer gns_live_sk_..." \
-H "Content-Type: application/json" \
-d '{
  "channel": "email",
  "recipient": "customer@acme.com",
  "subject": "Monthly Statement Ready",
  "body": "Your invoice for September 2026 is ready to review.",
  "html_body": "<h2>Invoice #4029</h2><p>Your statement is ready. <a href=\"https://acme.com/invoices\">View Invoice</a></p>",
  "reply_to": "support@acme.com"
}'

3. High-Throughput Postal Connection Pooling

GNS utilizes an asynchronous SMTP connection pool configured via GNS_SMTP_* environment variables:

• Keep-Alive Pool: Maintains warm SMTP sockets to eliminate TLS handshake latency.
• Failover Queue: If the primary Postal relay experiences transient backpressure, jobs are automatically held in RabbitMQ and retried with exponential backoff.
• Strict TLS: All outbound messages enforce opportunistic or mandatory STARTTLS.

4. Delivery Status Lifecycle

QUEUED ────────► PROCESSING ────────► DELIVERED
                     │
                     ▼ (Transient Network Error)
                   RETRYING ────────► FAILED (Audit logged in /activity)

Track every email transmission in real-time on the Delivery Activity screen.