Send email from Hetzner Cloud

Port 587 and HTTPS aren't blocked, so an app on Hetzner Cloud can send through Groundmail from day one, with no request to Hetzner:

Prerequisites

• A Groundmail account with a verified sending domain. A subdomain such as mail.yourdomain.com works well.
• An API key (gm_…) from API keys in the dashboard.

Send with the API

Give your app the key as the GROUNDMAIL_API_KEY environment variable, the same way it gets its other secrets: an .env file, a systemd unit, or your container's environment. Then send with an SDK.

Node.js

npm install groundmail

import { Groundmail } from 'groundmail'

const groundmail = new Groundmail(process.env.GROUNDMAIL_API_KEY)

await groundmail.emails.send({
  from: 'App <no-reply@mail.yourdomain.com>',
  to: 'user@example.com',
  subject: 'Reset your password',
  html: '<p>Click the link to reset your password.</p>',
})

Already on Nodemailer? Swap the SMTP transport for the Nodemailer transport, which sends over HTTPS, and keep your sendMail calls.

Python

pip install groundmail

import os
from groundmail import Groundmail

groundmail = Groundmail(os.environ["GROUNDMAIL_API_KEY"])
groundmail.emails.send(
    from_="App <no-reply@mail.yourdomain.com>",
    to="user@example.com",
    subject="Reset your password",
    html="<p>Click the link to reset your password.</p>",
)

Go, PHP and Ruby have SDKs too: see SDKs. Any other language can call POST https://api.groundmail.dev/emails with the key: see the API reference.

Keep SMTP

If your app can only send over SMTP, point it at Groundmail's relay on port 587:

If your app is set to port 465 (implicit TLS), change it to 587 with STARTTLS. See SMTP.

Running your apps with Coolify on a Hetzner server? See Send email from Coolify for where these settings go.

Troubleshooting