SMTP Relay

Connect any application via standard SMTP. Use your existing tools — no code changes required.

SMTP Settings

Host: smtp.grosend.com
Port: 587 (STARTTLS) or 465 (SSL/TLS)
Username: your-email@yourdomain.com
Password: your-generated-smtp-key

Ports 587 and 465 require authentication using your email address as the username and your generated SMTP key as the password. Port 25 is available but does not require authentication — use it only if your infrastructure doesn't support TLS.

Example: Node.js (Nodemailer)

Node.js

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransport({
  host: 'smtp.grosend.com',
  port: 587,
  secure: false,
  auth: {
    user: 'hello@yourdomain.com',
    pass: 'your-generated-smtp-key',
  },
});

await transporter.sendMail({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  subject: 'Hello from Grosend',
  html: '<h1>Sent via SMTP!</h1>',
});

Example: Python

Python

import smtplib
from email.mime.text import MIMEText

msg = MIMEText('<h1>Sent via SMTP!</h1>', 'html')
msg['Subject'] = 'Hello from Grosend'
msg['From'] = 'hello@yourdomain.com'
msg['To'] = 'user@example.com'

with smtplib.SMTP('smtp.grosend.com', 587) as server:
    server.starttls()
    server.login('hello@yourdomain.com', 'your-generated-smtp-key')
    server.send_message(msg)

Example: curl

Terminal

curl --url "smtp://smtp.grosend.com:587" \
  --ssl-reqd \
  --mail-from "hello@yourdomain.com" \
  --mail-rcpt "user@example.com" \
  --user "hello@yourdomain.com:your-generated-smtp-key" \
  -T email.eml

Get SMTP config via API

Terminal

curl https://api.grosend.com/api/v1/smtp \
  -H "Authorization: Bearer sv_live_..."

Response

{
  "host": "smtp.grosend.com",
  "port": 587,
  "ports": [25, 465, 587],
  "username": "hello@yourdomain.com",
  "password": "your-generated-smtp-key"
}

SMTP Settings

Host: smtp.grosend.com

Port: 587 (STARTTLS) or 465 (SSL/TLS)

Username: your-email@yourdomain.com

Password: your-generated-smtp-key

Example: Node.js (Nodemailer)

Node.js

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransport({
  host: 'smtp.grosend.com',
  port: 587,
  secure: false,
  auth: {
    user: 'hello@yourdomain.com',
    pass: 'your-generated-smtp-key',
  },
});

await transporter.sendMail({
  from: 'hello@yourdomain.com',
  to: 'user@example.com',
  subject: 'Hello from Grosend',
  html: '<h1>Sent via SMTP!</h1>',
});

Example: Python

Python

import smtplib
from email.mime.text import MIMEText

msg = MIMEText('<h1>Sent via SMTP!</h1>', 'html')
msg['Subject'] = 'Hello from Grosend'
msg['From'] = 'hello@yourdomain.com'
msg['To'] = 'user@example.com'

with smtplib.SMTP('smtp.grosend.com', 587) as server:
    server.starttls()
    server.login('hello@yourdomain.com', 'your-generated-smtp-key')
    server.send_message(msg)

curl --url "smtp://smtp.grosend.com:587" \ --ssl-reqd \ --mail-from "hello@yourdomain.com" \ --mail-rcpt "user@example.com" \ --user "hello@yourdomain.com:your-generated-smtp-key" \ -T email.eml