Technical Documentation · Engine v2.4

Integrate high-speed email delivery into your distributed microservices with our lightweight Node.js SDK.

Stable Release
|
Updated: Feb 2026

Introduction

VarboxMail provides a low-latency gateway between your application logic and global email relays. Unlike traditional providers, we emphasize Protocol Isolation—ensuring your sensitive data remains within your specified infrastructure boundaries.

Technical Density

Atomic tracking at every hop: injection success, relay latency, city-level geodata.

Zero-Trust Auth

SDK ↔ Control Plane secured by encrypted handshakes and rotating system tokens.

Quick Start

01

Install Core SDK

terminal
1npm install varboxmail
02

Initialize Client

index.ts
1import { VarboxMail } from 'varboxmail';
2 
3const sm = new VarboxMail({
4 apiKey: process.env.VARBOX_API_KEY
5});
6 
7await sm.sendEmail({
8 to: 'user@example.com',
9 subject: 'Infrastructure Protocol',
10 template: 'welcome_v1',
11 data: { name: 'Dev' }
12});

Complex Payloads

Utilize batch injection protocols for high-throughput transactional distribution.

batch-dispatch.ts
1await sm.sendCampaign({
2 template: 'onboarding_sequence',
3 recipients: [
4 { email: 'node_01@cluster.io', data: { id: '001' } },
5 { email: 'node_02@cluster.io', data: { id: '002' } }
6 ],
7 tags: ['production_cluster']
8});

Fault Tolerance

Architecture Note

The SDK maintains an internal state machine for relay failover. Use strict error boundary patterns to handle region-wide outages.

recovery.ts
1try {
2 const stats = await sm.getAnalytics('24h');
3} catch (e: any) {
4 if (e.statusCode === 401) {
5 console.error('API_KEY_EXPIRED');
6 }
7}