MailShogun

Guide

Connect over SMTP

Connect your site, CRM or server. Server, port 2525, STARTTLS, and the username and password for a verified domain.

Before you start

Have a verified domain and its SMTP credentials ready. Your panel password and an API key cannot authenticate an SMTP connection.

Set up your account and domain

Reviewed on September 11, 2026

Connection details

Server and port are the same for everyone. The password is the one shown when you create each SMTP user.

Server
smtp.mailshogun.com
Port
2525
Security
STARTTLS
Authentication
LOGIN / PLAIN

Use smtp.mailshogun.com:2525 with STARTTLS and authentication. Examples for other providers using 465 or 587 do not apply to this connection.

Dialogue with the server

Three steps: connect, sign in and get the 250 OK reply.

Session

220 smtp.mailshogun.com:2525 ESMTP
EHLO client.local
250-STARTTLS
STARTTLS
220 2.0.0 Ready to start TLS

TLS ready

Create SMTP username and password

Open a verified domain. Under Connection, create the SMTP user. Username and password are shown once: store them in your app.

Without a verified domain there is no SMTP user. Without a tier or a card, the panel will not let you create them.

Open Domains

Examples

Configuration snippets for an existing application. Install PHPMailer with Composer or Nodemailer with npm and import the library. Set MAILSHOGUN_SMTP_USER and MAILSHOGUN_SMTP_PASSWORD in the server environment. Also configure a sender on the verified domain.

use PHPMailer\PHPMailer\PHPMailer;
require 'vendor/autoload.php';

$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host       = 'smtp.mailshogun.com';
$mail->Port       = 2525;
$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
$mail->SMTPAuth   = true;
$mail->Username   = getenv('MAILSHOGUN_SMTP_USER');
$mail->Password   = getenv('MAILSHOGUN_SMTP_PASSWORD');

WordPress includes PHPMailer. Add this hook to your own plugin; also configure the wp_mail() sender on your verified domain. Keep passwords out of themes and the repository.

add_action('phpmailer_init', function ($phpmailer) {
    $phpmailer->isSMTP();
    $phpmailer->Host       = 'smtp.mailshogun.com';
    $phpmailer->Port       = 2525;
    $phpmailer->SMTPSecure = 'tls';   // STARTTLS
    $phpmailer->SMTPAuth   = true;
    $phpmailer->Username   = getenv('MAILSHOGUN_SMTP_USER');
    $phpmailer->Password   = getenv('MAILSHOGUN_SMTP_PASSWORD');
});

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'smtp.mailshogun.com',
  port: 2525,
  secure: false,        // STARTTLS
  requireTLS: true,
  auth: { user: process.env.MAILSHOGUN_SMTP_USER, pass: process.env.MAILSHOGUN_SMTP_PASSWORD },
});

Common failures

  • Wrong port

    Check that your application uses the specified host and port 2525. Also check that your hosting allows outbound connections to this port.

  • Missing STARTTLS

    Port 2525 expects STARTTLS (secure: false and requireTLS in Nodemailer; ENCRYPTION_STARTTLS in PHPMailer).

  • Unverified domain

    The SMTP user is tied to a verified domain. If DNS has not passed yet, create or verify the domain first.

  • No tier or card

    Creating SMTP users and sending needs a contracted tier and a saved card.

Open the panel Getting started

Check the result

  • Set a sender on the verified domain and a recipient you control. The examples in this guide configure a connection; they do not send by themselves.
  • A 250 after message acceptance confirms queuing. Check Statistics and the recipient mailbox afterwards.
  • For a timeout, check outbound TCP access to port 2525 with your provider. For AUTH errors, check SMTP credentials. For TLS errors, check the hostname and certificate; keep TLS certificate validation enabled.

Open Statistics

Continue with

Still stuck? Share the error code, time and affected domain with support. Remove passwords, API keys and message contents. Support