Sending over SMTP

For anything that already speaks SMTP. Four settings:

Host	smtp.mg.truo.cloud
Port	465
Encryption	Implicit TLS (SMTPS) — TLS from the first byte, no upgrade
Username / password	From your panel

Port 465 only

There is no port 587 and no STARTTLS.

Many frameworks default to 587, so their out-of-the-box configuration will not connect — and it fails as a timeout or a dropped connection rather than an authentication error, which sends people looking in the wrong place.

If your library has a secure / ssl / tls boolean, it must be on. If it has a separate STARTTLS option, it must be off.

The credentials are not your API key

The SMTP username and password are issued separately from the mg_live_... key, and neither works in the other’s place. Both are in your panel, on the service’s SMTP tab. The username is not an email address.

Configuration

Nodemailer

import nodemailer from "nodemailer";

const transport = nodemailer.createTransport({
  host: "smtp.mg.truo.cloud",
  port: 465,
  secure: true, // implicit TLS. `false` here attempts STARTTLS and stalls.
  auth: {
    user: process.env.MG_SMTP_USER,
    pass: process.env.MG_SMTP_PASSWORD,
  },
});

await transport.sendMail({
  from: "Acme <no-reply@acme.com>",
  to: "customer@example.com",
  subject: "Your receipt",
  html: "<p>Thanks for your order.</p>",
});

Python

import os, smtplib
from email.message import EmailMessage

msg = EmailMessage()
msg["From"] = "Acme <no-reply@acme.com>"
msg["To"] = "customer@example.com"
msg["Subject"] = "Your receipt"
msg.set_content("Thanks for your order.")

# SMTP_SSL, not SMTP().starttls(): the connection is TLS from the start.
with smtplib.SMTP_SSL("smtp.mg.truo.cloud", 465) as s:
    s.login(os.environ["MG_SMTP_USER"], os.environ["MG_SMTP_PASSWORD"])
    s.send_message(msg)

PHPMailer

$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host       = 'smtp.mg.truo.cloud';
$mail->Port       = 465;
$mail->SMTPSecure = PHPMailer::ENCRYPTION_SMTPS; // not ENCRYPTION_STARTTLS
$mail->SMTPAuth   = true;
$mail->Username   = getenv('MG_SMTP_USER');
$mail->Password   = getenv('MG_SMTP_PASSWORD');

$mail->setFrom('no-reply@acme.com', 'Acme');
$mail->addAddress('customer@example.com');
$mail->Subject = 'Your receipt';
$mail->msgHTML('<p>Thanks for your order.</p>');
$mail->send();

WordPress

// A small mu-plugin. Define the constants in wp-config.php, not here.
add_action('phpmailer_init', function ($mail) {
    $mail->isSMTP();
    $mail->Host       = 'smtp.mg.truo.cloud';
    $mail->Port       = 465;
    $mail->SMTPSecure = 'ssl';
    $mail->SMTPAuth   = true;
    $mail->Username   = MG_SMTP_USER;
    $mail->Password   = MG_SMTP_PASSWORD;
});

// WordPress sends as wordpress@yourdomain unless you say otherwise, and that
// address is usually on a domain you never verified.
add_filter('wp_mail_from', fn () => 'no-reply@acme.com');
add_filter('wp_mail_from_name', fn () => 'Acme');

What differs from HTTP

Same domains, same quota, same stats. Two practical differences:

• Errors arrive as SMTP replies, not JSON. An unverified sending domain is a 554 when the message is handed over, not a 403.
• The sender still has to be a verified domain, and something in your stack may be rewriting it. The rejected address is the one that actually left your application, not the one you typed. Log it before assuming the verification is at fault.