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Point, authenticate, send.

justsmtp is a drop-in SMTP relay in front of Amazon SES. Point your existing mailer at smtp.justsmtp.com, authenticate with a credential pair generated in the dashboard, and send. No AWS account, no IAM policies.

Connection settings

These don't change — safe to hard-code or drop straight into an env file.

host	smtp.justsmtp.com
port (STARTTLS)	587
port (dev / restrictive networks)	2525 — STARTTLS, same credentials
auth mechanisms	AUTH LOGIN, AUTH PLAIN
username / password	Generated per credential pair in the dashboard. Shown once at creation — store it in your secrets manager or .env, not source control.

How it works

Your application connects to smtp.justsmtp.com over STARTTLS and authenticates with the username and password from a credential pair.

We accept the message over SMTP, check the sending domain's DKIM and SPF, and hand it off to Amazon SES for delivery.

Every attempt — sent, deferred, bounced, dropped — lands in your activity log with the real upstream SMTP response. We don't retain message bodies; the log keeps metadata and the subject line only.

Integrations

justsmtp works with any SMTP client. Swap the host, port and credentials into your existing mailer — nothing else changes.

Node.js nodemailer

// npm install nodemailer
import nodemailer from 'nodemailer';

const transport = nodemailer.createTransport({
  host: 'smtp.justsmtp.com',
  port: 587,
  secure: false,
  auth: { user: process.env.SMTP_USER, pass: process.env.SMTP_PASS },
});

await transport.sendMail({
  from: '"Acme" <hello@mail.acme.io>',
  to: 'sarah@example.com',
  subject: 'Welcome to Acme',
  html: '<b>You are in.</b>',
});

Python smtplib — stdlib, no install

import os, smtplib
from email.message import EmailMessage

msg = EmailMessage()
msg["From"] = "Acme <hello@mail.acme.io>"
msg["To"] = "sarah@example.com"
msg["Subject"] = "Welcome to Acme"
msg.set_content("You are in.")

with smtplib.SMTP("smtp.justsmtp.com", 587) as server:
    server.starttls()
    server.login(os.environ["SMTP_USER"], os.environ["SMTP_PASS"])
    server.send_message(msg)

Ruby mail

# gem install mail
require 'mail'

Mail.defaults do
  delivery_method :smtp, {
    address:              'smtp.justsmtp.com',
    port:                 587,
    user_name:            ENV['SMTP_USER'],
    password:             ENV['SMTP_PASS'],
    authentication:       :plain,
    enable_starttls_auto: true,
  }
end

Mail.deliver do
  from    'hello@mail.acme.io'
  to      'sarah@example.com'
  subject 'Welcome to Acme'
  body    'You are in.'
end

PHP symfony/mailer

// composer require symfony/mailer
use Symfony\Component\Mailer\Transport;
use Symfony\Component\Mailer\Mailer;
use Symfony\Component\Mime\Email;

$transport = Transport::fromDsn(
  'smtp://'.getenv('SMTP_USER').':'.getenv('SMTP_PASS').'@smtp.justsmtp.com:587'
);
$mailer = new Mailer($transport);

$mailer->send((new Email())
  ->from('hello@mail.acme.io')
  ->to('sarah@example.com')
  ->subject('Welcome to Acme')
  ->html('<b>You are in.</b>'));