---
title: "SMTP relay | Prontuno"
description: "Connect any app or framework that already speaks SMTP. Route your transactional email through Prontuno without rewriting the code that sends it."
canonical: https://prontuno.com/features/smtp-relay/
---

# Keep your existing mail integration.

**SMTP relay · STARTTLS · SSL/TLS**

Connect any app or framework that already speaks SMTP. Route your transactional email through Prontuno without rewriting the code that sends it.

[Request access](https://app.prontuno.com/get-started/) · [Read the SMTP setup guide](https://prontuno.com/docs/sending/send-email-with-smtp/)

## Connection settings

### Example SMTP connection

| Setting | Value |
| --- | --- |
| Host | `smtp.prontuno.net` |
| Port | `587` |
| Security | `STARTTLS` |

```text
C STARTTLS
C AUTH PLAIN ••••••••••••
C MAIL FROM:<hello@example.com>
S 250 Message queued
```

Also available: 465 (SSL/TLS), 2525 and 25 (STARTTLS).

## Connect the tools you already use

SMTP suits apps that already send mail, such as frameworks, CMSs, and off-the-shelf tools. For new code, the Email API adds batching, idempotent requests, and structured errors.

### Bring existing apps

Change a few settings to point your app, framework, or CMS at Prontuno.

### Manage credentials

Create, reset, and revoke SMTP credentials from your account whenever you need to.

### Follow delivery

Messages sent over SMTP appear in your email logs alongside everything sent through the API.

## Drop-in settings for your framework

Most frameworks need only a host, a port, and a username and password.

### Ports and encryption

| Port | Encryption | Notes |
| --- | --- | --- |
| 587 | STARTTLS | Recommended. |
| 465 | SSL/TLS | The connection is encrypted from the start (implicit TLS). |
| 2525 | STARTTLS | Alternative for networks that block ports 587 and 465. |
| 25 | STARTTLS | Standard SMTP port. Often blocked for outgoing mail by cloud providers. |

### Username is not a secret

The SMTP username identifies the credential. It can be stored in application config like any other setting.

### Password is shown once

The password is displayed only when the credential is created. It can be reset from your account at any time.

### Tied to a verified domain

Each credential belongs to one verified domain and sends from addresses on that domain.

### Configure your mailer examples

#### Laravel

```env
MAIL_MAILER=smtp
MAIL_HOST=smtp.prontuno.net
MAIL_PORT=587
MAIL_USERNAME=your_smtp_username
MAIL_PASSWORD=your_smtp_password
MAIL_FROM_ADDRESS=hello@example.com
```

#### Nodemailer

```js
import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'smtp.prontuno.net',
  port: 587,
  secure: false,
  requireTLS: true,
  auth: {
    user: process.env.PRONTUNO_SMTP_USERNAME,
    pass: process.env.PRONTUNO_SMTP_PASSWORD,
  },
});
```

#### Django

```python
import os

EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
EMAIL_HOST = "smtp.prontuno.net"
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = os.environ["PRONTUNO_SMTP_USERNAME"]
EMAIL_HOST_PASSWORD = os.environ["PRONTUNO_SMTP_PASSWORD"]
DEFAULT_FROM_EMAIL = "hello@example.com"
```

#### Rails

```ruby
config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  address: "smtp.prontuno.net",
  port: 587,
  user_name: ENV["PRONTUNO_SMTP_USERNAME"],
  password: ENV["PRONTUNO_SMTP_PASSWORD"],
  authentication: :plain,
  enable_starttls: :always
}
```

## Send through the SMTP relay

1. Request access and verify a sending domain.
2. Create SMTP credentials for that domain.
3. Update your mail settings and send a test message.

[Read the SMTP setup guide](https://prontuno.com/docs/sending/send-email-with-smtp/)

## Explore more of Prontuno

- [Email API](https://prontuno.com/features/email-api/) — Send email with one HTTP request.
- [Webhooks](https://prontuno.com/features/webhooks/) — Get delivery events in real time.
- [Domain authentication](https://prontuno.com/features/domain-authentication/) — Set up SPF, DKIM, and DMARC.
- [Dedicated IP](https://prontuno.com/features/dedicated-ip/) — An IP reserved for your team.

## Request access

Ready to send with Prontuno? Request access and tell us about your sending needs. Applications are reviewed within 24 hours.

[Request access](https://app.prontuno.com/get-started/)