Email API for Developers — Send Transactional & Bulk Email via REST API & SMTP
Integrate email in minutes with a clean REST API, SMTP relay and SDKs for every stack. Fire transactional and bulk email, personalize with dynamic templates, and track every open, click and bounce in real time — across India and 190+ countries, all from one multichannel API that also does SMS and WhatsApp.
Send your first email in one REST call
Authenticate with a bearer token, POST a JSON body and you are live. Use template_id with variables for dynamic content and an idempotency_key to make retries safe.
# POST a transactional email curl -X POST https://api.smsgatewayprovider.com/v1/email/send \ -H "Authorization: Bearer YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "from": "orders@yourdomain.com", "to": "customer@example.com", "subject": "Your order is confirmed", "html": "<h1>Thanks for your order</h1>", "text": "Thanks for your order", "template_id": "order_confirmation", "variables": { "name": "Arjun", "order_id": "INV-4821" }, "idempotency_key": "order-4821-confirm" }'
// 200 OK { "message_id": "em_9f3c21a7b4e0", "status": "queued", "accepted": [ "customer@example.com" ], "rejected": [ ] }
- HTTPS-only endpoint with bearer-token auth
- Send raw
html/textor a storedtemplate_id idempotency_keyprevents duplicate sends on retry
Why developers choose our Email API
Ship in minutes
A single REST call or SMTP config gets your first email out the door — no lengthy onboarding.
High inbox delivery
Authenticated sending with SPF, DKIM and DMARC plus IP warmup keeps mail out of spam.
99.9% uptime
Resilient, monitored infrastructure keeps your transactional and bulk mail flowing.
24×7 human support
Real engineers on call any time across India and globally to unblock your integration.
One integration, two ways to send — REST API or SMTP relay
Use the REST API when you want full control, webhooks and rich responses. Use SMTP relay when you want to point an existing app or framework at our servers with a few lines of config.
| Capability | Email API (REST) | SMTP Relay |
|---|---|---|
| Integration method | HTTPS POST to a JSON endpoint | Standard SMTP host, port & credentials |
| Best for | New apps, backends, event-driven sending | Existing apps & frameworks already using SMTP |
| Setup speed | Minutes — drop in an API key | Minutes — swap SMTP host & login |
| Sending speed | High throughput, batched calls | High throughput over persistent connections |
| Batch/bulk personalization | Native batch endpoint with per-recipient variables | Per-message via headers/merge fields |
| Templates & dynamic variables | Full — stored templates + variables | Supported via template headers |
| Webhooks & event tracking | Full event stream (delivered, open, click, bounce) | Delivery events via webhooks |
| Inbound parsing | Yes — inbound routes post JSON to your app | Yes — via inbound routing rules |
| Ideal user | Developers wanting rich control & JSON responses | Teams migrating an existing SMTP codebase |
Sending high volume campaigns? See our API & SMTP bulk email gateway.
Built for every stack — SDKs
Official SDKs and idiomatic snippets so you can call the Email API natively in your language of choice, or hit the raw REST endpoint with cURL.
Node.js
npm install and send with a promise-based client and full TypeScript types.
PHP
Composer package with a simple client for transactional and bulk sends.
Python
pip-installable SDK with async support for high-throughput workloads.
Ruby
Gem with a clean object model for messages, templates and webhooks.
Java
Maven/Gradle artifact for JVM services and enterprise backends.
Go
Lightweight, dependency-free client for fast, concurrent sending.
.NET
NuGet package for C# and ASP.NET transactional email.
Laravel
Drop-in mail driver — configure once and use Laravel’s Mailable classes.
cURL
No SDK needed — call the REST endpoint directly from any shell or tool.
Core Email API features
Dynamic templates & personalization
Store reusable templates and inject per-recipient variables at send time.
Attachments, CC/BCC & headers
Add file attachments, CC/BCC recipients and custom headers on any message.
Batch & bulk sending
Send to thousands in one call with per-recipient personalization and merge fields.
Idempotency keys & retries
Safe retries with an idempotency_key so a resent request never double-sends.
Sandbox & test keys
Test-mode API keys and a sandbox let you build safely without sending real mail.
Rate limits & throughput
Transparent rate limits with headroom to scale to high-volume sending.
Real-time events & webhooks
Every email generates events you can subscribe to. We POST a signed JSON payload to your endpoint the moment something happens — so you can update records, retry, or suppress addresses automatically.
// POST to your webhook URL { "event": "delivered", "message_id": "em_9f3c21a7b4e0", "email": "customer@example.com", "timestamp": "2026-08-14T09:12:04Z", "smtp_response": "250 2.0.0 OK", "tags": [ "order", "transactional" ] }
Event types you can subscribe to
- delivered — accepted by the recipient server
- open — the recipient opened the message
- click — a tracked link was clicked
- bounce — hard or soft bounce with reason
- complaint — recipient marked as spam
- unsubscribe — recipient opted out
- deferred — delivery temporarily delayed
Inbound email parsing
Point an MX record or address at our inbound route and every reply is parsed into clean JSON — sender, subject, body, headers and attachments — then POSTed to your webhook. Perfect for reply handling, support ticketing, and email-to-app workflows without running your own mail server.
Parsed to JSON
Headers, plain text, HTML and attachments extracted into structured fields.
Route by address
Match on recipient address or pattern to send different mail to different endpoints.
Reply threading
Message IDs and references preserved so you can thread conversations in your app.
Deliverability & inbox placement
Great APIs are worthless if mail lands in spam. We build authentication, reputation and hygiene into the platform so your transactional and bulk email reaches the inbox.
SPF, DKIM & DMARC
Guided domain authentication so mailbox providers trust your sending domain.
Dedicated/shared IP + warmup
Choose shared or dedicated IPs with automated warmup to build sender reputation.
Suppression & bounce handling
Automatic suppression lists keep bounces and complaints from hurting your reputation.
Use cases
OTP & 2FA
Deliver one-time passcodes and verification links the instant a user requests them.
Password reset
Send secure, time-boxed reset links with dynamic templates and tracking.
Order & payment confirmations
Trigger receipts and invoices the moment a transaction completes.
Notifications & alerts
Account activity, system alerts and reminders driven by app events.
Onboarding
Welcome sequences and drip series to activate new users.
Inbound reply handling
Parse replies into JSON to power support desks and email-to-app flows.
An email platform your engineers can trust
Trusted by 5,000+ businesses across India and 190+ countries, with 15+ years in messaging — one multichannel API for email, SMS and WhatsApp, backed by real support.
Fast, clean API
Predictable JSON, clear errors and SDKs so you integrate in minutes, not weeks.
Multichannel, one API
Add SMS and WhatsApp alongside email without a second integration.
99.9% uptime
Monitored, redundant infrastructure keeps critical mail flowing.
24×7 support, India + global
Human help any time as you build, launch and scale.
Transparent, volume-based pricing
Start on a free sandbox, then pay for what you send — transactional or bulk. Rates drop as your volume grows, and one account covers email, SMS and WhatsApp.
Email API FAQs
What is an email API?
message_id and status for every send.How do I send an email via REST API?
/v1/email/send with an Authorization: Bearer YOUR_API_KEY header and a JSON body containing from, to, subject and either html/text or a template_id with variables. You get back a message_id and a status of queued.What is the difference between an email API and SMTP relay?
Which languages and SDKs are supported?
How fast can I start sending?
Do you handle SPF, DKIM and DMARC?
Can I receive and parse inbound emails?
How do webhooks and event tracking work?
message_id, recipient, timestamp and SMTP response so you can update records in real time.What are the rate limits and how do you handle high volume?
Do you support idempotency and retries?
idempotency_key with each send. If a request is retried — after a timeout, for example — we recognise the key and never send a duplicate, so retries are always safe.