> ## Documentation Index
> Fetch the complete documentation index at: https://docs.unosend.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Unosend is a transactional email service for developers. Send emails with REST API or SMTP.

Unosend is a dedicated transactional email service designed to deliver time-sensitive emails triggered by user actions — such as OTPs, order confirmations, password resets, invoices, and more. It ensures faster delivery, higher inbox placement, and reliable security.

<Note>
  Unosend is for sending transactional emails only. Marketing or bulk promotional emails are not supported to maintain maximum deliverability and sender reputation.
</Note>

## Features

* **REST API & SMTP** — Send via `api.unosend.co` or `smtp.unosend.co:587`
* **Email templates** — Create, manage, and send with dynamic merge tags
* **Domain authentication** — SPF, DKIM, and DMARC verification
* **Real-time webhooks** — Get notified on delivery, bounce, open, and click events
* **Suppression management** — Automatic bounce/complaint handling + manual suppression lists
* **Email logs & exports** — Full delivery logs with export capability
* **File cache** — Upload and reuse attachments/inline images across emails
* **Dedicated IP** — Available for high-volume senders
* **Open & click tracking** — Built-in tracking with per-email control
* **Batch sending** — Send to multiple recipients in a single API call

```bash theme={null}
curl -X POST https://api.unosend.co/v1/email \
  -H "Authorization: Bearer un_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "from": {"address": "hello@yourdomain.com", "name": "Your App"},
    "to": [{"email_address": {"address": "user@example.com", "name": "User"}}],
    "subject": "Hello from Unosend",
    "htmlbody": "<p>Your first email.</p>"
  }'
```

## Get Started

<CardGroup cols={2}>
  <Card icon="bolt" href="/quickstart" title="Quick Start">
    Send your first email in 5 minutes
  </Card>

  <Card icon="key" href="/authentication" title="Authentication">
    API keys and security
  </Card>

  <Card icon="globe" href="/guides/domain-verification" title="Domain Setup">
    Verify your sending domain
  </Card>

  <Card icon="code" href="/api-reference/introduction" title="API Reference">
    Full endpoint documentation
  </Card>
</CardGroup>