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Transactional Email at Wire Speed.

Engineered with dual-lane IP isolation, instant OTP delivery, automated 2048-bit DKIM rotation, and developer-first pricing in ₹ INR.

Start Sending Free (3,000/mo)Live Telemetry Engine →
API Latency< 45msGlobal Edge Ingestion
Inbox Placement99.99%Dual-Lane IP Protection
Outbox Reliability100%Zero Dropped Messages
India-First Cost₹0.03Per Email Overage
KumoMTA Engine[Bare-Metal Core]
Next.js 14[Fullstack]
Node.js[Runtime]
TypeScript[Type Safe]
Python[Async SDK]
Go[Concurrency]
Rust[Zero Cost]
Supabase Postgres[Source of Truth]
BullMQ & Redis[Priority Queues]
Razorpay[UPI & INR Billing]
Haraka SMTP[Inbound Parsing]
DKIM 2048[Cryptography]
DMARC & SPF[Alignment]
TLS 1.3[Transport Security]
KumoMTA Engine[Bare-Metal Core]
Next.js 14[Fullstack]
Node.js[Runtime]
TypeScript[Type Safe]
Python[Async SDK]
Go[Concurrency]
Rust[Zero Cost]
Supabase Postgres[Source of Truth]
BullMQ & Redis[Priority Queues]
Razorpay[UPI & INR Billing]
Haraka SMTP[Inbound Parsing]
DKIM 2048[Cryptography]
DMARC & SPF[Alignment]
TLS 1.3[Transport Security]
Developer First SDKs

Send in 3 lines of code. Any language.

Native bindings across 13 languages and frameworks. Complete with automated idempotency, dual-lane tagging, and robust RFC 5322 compliance.

200 OK • 38ms
Node.js•Native fetch (Node 18+, Bun, Deno)
1// Zero dependencies - works in Node 18+, Next.js, Express & Bun
2const response = await fetch('https://api.sendoff.in/v1/emails', {
3 method: 'POST',
4 headers: {
5 'Authorization': `Bearer ${process.env.SENDOFF_API_KEY}`,
6 'Content-Type': 'application/json',
7 'Idempotency-Key': crypto.randomUUID(),
8 },
9 body: JSON.stringify({
10 from: 'Acme Security <security@yourdomain.com>',
11 to: [ 'user@example.com'],
12 subject: 'Your one-time code: 849201',
13 html: '<strong>Your verification code is 849201.</strong>',
14 lane: 'transactional', // Sub-50ms Fast Lane
15 tags: [{ name: 'category', value: 'auth-otp' }]
16 })
17});
18 
19const data = await response.json();
20return data.id; // Dispatched: "msg_89f02..."
KumoMTA Direct Queue
Queue: Bare Metal
Developer Experience

First-class developer experience

We are a team of engineers who love building tools for other engineers. Our goal is to create the email platform we've always wished we had — one that just works.

HTTP 200:just now
{ "id": "8a5821c1-a39e-49bb-8218-a7fbe0e3308f" }
HTTP 200:2s ago
{ "id": "738079a5-2ee9-4623-b8bb-1b58583d46a9" }
HTTP 200:4s ago
{ "id": "2ccc3edb-9890-481b-99c8-de4552c234a0" }
HTTP 200:7s ago
{ "id": "2d984427-89d5-4c99-94d6-134d4159d866" }
HTTP 200:10s ago
{ "id": "48865d4f-cb89-41ac-b3cf-821457561310" }

Test mode

Simulate events and experiment with our API without the risk of accidentally sending real emails to real people.

Learn more
webhook.sendoff.in
Active Stream • TLS 1.3
deliveredjust now
to noah@xerox.com with subject Get Started
agentProtonMailProtonMail•osmacOSmacOS
opened2s ago
from lucas@gmail.com with subject Welcome
agentGmailGmail•osWindowsWindows
clicked4s ago
from liam@figma.com on Verify Account
agentSparkSpark•osmacOSmacOS
bounced6s ago
to invalid-user@domain.com with type MX_NotFound
agentGmailGmail•osWindowsWindows

Modular webhooks

Receive real-time notifications directly to your server. Every time an email is delivered, opened, bounces, or a link is clicked.

Learn more
Modern Email Toolchain

Develop emails using React

Write clean, component-driven emails with type safety. Preview live rendered HTML in real-time with responsive device simulation.

Explorerv1.2
emails
Sub-50ms Lane
React Email 3.x
welcome-email.tsx
1import { Html, Head, Preview, Body, Container, Section, Text, Button, Hr } from '@react-email/components';
2import { SendOff } from '@sendoff/client';
3
4const sendoff = new SendOff({
5 apiKey: process.env.SENDOFF_API_KEY,
6 endpoint: 'https://api.sendoff.in/v1'
7});
8
9export default function WelcomeEmail({ name = 'Alex', team = 'Acme Corp' }) {
10 return (
11 <Html>
12 <Head />
13 <Preview>Welcome to SendOFF transactional engine</Preview>
14 <Body className="bg-[#0b0b0d] text-[#fafafa] font-sans p-6">
15 <Container className="max-w-[560px] mx-auto p-8 rounded-2xl border border-neutral-800 bg-[#141417]">
16 <Text className="text-2xl font-bold tracking-tight">Welcome aboard, {name} 👋</Text>
17 <Text className="text-neutral-400 text-sm leading-relaxed mt-2">
18 Your SendOFF workspace <strong>{team}</strong> is provisioned and ready for sub-50ms email delivery.
19 </Text>
20 <Section className="my-6">
21 <Button href="https://app.sendoff.in/dashboard" className="bg-white text-black font-semibold px-6 py-3 rounded-xl text-sm">
22 Open SendOFF Dashboard →
23 </Button>
24 </Section>
25 <Hr className="border-neutral-800 my-6" />
26 <Text className="text-xs text-neutral-500">
27 Sent via SendOFF High-Priority Transactional Lane • Sub-50ms Global Delivery
28 </Text>
29 </Container>
30 </Body>
31 </Html>
32 );
33}
Subject:Welcome to SendOFF transactional engine 👋
Live Render
SO
SendOFF
Sub-50ms Lane

Welcome aboard, Alex 👋

Your SendOFF workspace Acme Corp is provisioned and ready for sub-50ms email delivery across isolated transactional IP pools.

Open SendOFF Dashboard →

Sent by SendOFF Engine to alex@example.com

Sub-50ms transactional routing • DKIM 2048-bit Verified

git:(main)0 errors•0 warnings
Prettier
Full-Spectrum Observability

Go beyond delivery.
Total telemetry & live health.

Every send is measured with microsecond accuracy. Monitor inbox placement across top ISPs, wire-speed latency percentiles, and automatic suppression defense in real time.

Live Inbox Placement99.99% Target Met
99.98%+0.12% vs avg

Measured across verified DMARC aggregates and TLS socket handshakes. Zero traffic routed to shared low-reputation IP pools.

Volume148,920
Bounce Rate0.01%
Complaints0.00%
Wire LatencyEdge to Queue
30msmedian p50

Postgres outbox write + KumoMTA socket queue dispatch under wire speed.

p50 Median30ms
p95 High SLA42ms
p99 Tail62ms
Reputation Guard

Auto-Suppression

Zero spam trap pollution. Hard bounces and FBL complaints are quarantined in 0ms with tenant-isolated suppression lists.

Hard Bounce Quarantine
One-Click RFC 8058 Unsub
Tenant Isolation via RLS

Top Mailbox Provider PlacementGlobal Seed Audited

Continuously monitored via seed mailboxes across consumer and enterprise providers.

View deliverability docs
GoogleGoogle
99.99%Gmail & Workspace
MicrosoftMicrosoft
99.95%Office 365 & Outlook
YahooYahoo
99.92%Yahoo & AOL Mail
AppleApple
100.0%iCloud & Apple Mail
Clear & Predictable Plans

Simple pricing in Indian Rupees.

Start free with 3,000 emails/month. Scale as your customer base expands.

Monthly BillingAnnual BillingSave ~17%
🌍 Global & Country-Localized Pricing (Starter, Pro, Advanced)

Free

Ideal for indie hackers, prototyping, and small production apps.

₹0/month
  • 3,000 emails per month
  • 100 emails daily hard cap
  • 1 Workspace only
  • Solo Developer (0 member invites)
  • 1 Verified Sending Domain
  • 1 Ingestion Webhook Endpoint
  • 3-day email & audit log history
  • Standard Transactional Lane
Start Free
Most Popular

Starter

For early-stage startups and teams building transactional workflows.

₹999/month
  • 50,000 emails per month
  • 1,000 emails daily send quota
  • Up to 3 Workspaces
  • Up to 3 Team Member Seats
  • 3 Verified Custom Domains
  • 5 Ingestion Webhooks
  • 14-day email & audit log history
  • Dual-Lane Routing (Fast OTP & Bulk)
  • Email Support (4-hour SLA)
Get Starter

Growth

For growing companies with high transactional and product volume.

₹3,999/month
  • 250,000 emails per month
  • 10,000 emails daily send quota
  • Up to 10 Workspaces
  • Up to 10 Team Member Seats
  • 10 Verified Custom Domains
  • 20 Ingestion Webhooks & Alerts
  • 30-day email & audit log history
  • Dedicated Warm IP Option
  • Inbound MX Subdomain Routing
  • Priority Technical Support
Get Growth

Scale

For high-throughput platforms and enterprise applications.

Contact Sales
  • Unlimited / Custom Monthly Volume
  • Unlimited Daily Sends
  • Unlimited Workspaces & Team Seats
  • Unlimited Verified Domains
  • Unlimited Webhooks & Raw S3 Export
  • 90-day retention & Cold Storage
  • Dedicated IP Pool + Custom Warmup
  • Custom KumoMTA Policies & 99.99% SLA
Contact Sales
Frequently Asked Questions

Engineered with transparency.

Stop losing emails to the spam folder.

Switch to SendOFF in under 5 minutes. Deliver your OTPs and transactional mail at line rate.

Start Sending Free (3,000/mo)Talk to Engineering (team@sendoff.in)