Everything you need to run email on MailDog

Services

Every MailDog account includes the following services at no extra cost. Use as many or as few as you need.

Quickstart

Get from zero to your first authenticated email delivery in five minutes. This assumes you own a domain and have access to its DNS.

1. 1

   Sign in and add a domain

   Go to Panel → Domains → Add Domain, enter the domain you want to send from (e.g. yourco.com). MailDog auto-generates a unique DKIM keypair for your domain.

2. 2

   Add the 4 DNS records

   The popup shows exactly what to paste into your DNS provider (Cloudflare, Route53, Namecheap, etc.). You'll add one MX, one SPF (TXT), one DKIM (CNAME), and one DMARC (TXT). The DKIM is a CNAME pointing to a record MailDog publishes and owns — so we can rotate your keys without you touching DNS again.

3. 3

   Verify the records

   Click the green Verify DNS button on your domain row. All four indicators should turn green within a couple of minutes. If something stays red, hover it for the exact query that failed.

4. 4

   Create an SMTP account

   Panel → Mailboxes → Add Mailbox. Pick an address like noreply@yourco.com and a password. These are the credentials your app will use to authenticate.

5. 5

   Send your first email

   Plug the credentials into your application, or use the built-in SMTP Tester to verify delivery without writing any code.

Outbound SMTP

Once your domain is verified, authenticate against mail.maildog.io with your SMTP account credentials. MailDog supports all the standard submission ports:

Example: Node.js (nodemailer)

import nodemailer from "nodemailer";

const transporter = nodemailer.createTransport({
  host: "mail.maildog.io",
  port: 587,
  secure: false,          // STARTTLS upgrades the connection
  auth: {
    user: "noreply@yourco.com",
    pass: "your-smtp-password",
  },
});

await transporter.sendMail({
  from: '"Your Co" <noreply@yourco.com>',
  to: "customer@example.com",
  subject: "Welcome!",
  text: "Thanks for signing up.",
  html: "<p>Thanks for signing up.</p>",
});

Example: Python

import smtplib
from email.message import EmailMessage

msg = EmailMessage()
msg["Subject"] = "Welcome!"
msg["From"] = "Your Co <noreply@yourco.com>"
msg["To"] = "customer@example.com"
msg.set_content("Thanks for signing up.")

with smtplib.SMTP("mail.maildog.io", 587) as s:
    s.starttls()
    s.login("noreply@yourco.com", "your-smtp-password")
    s.send_message(msg)

Example: curl

curl --url "smtp://mail.maildog.io:587" --ssl-reqd \
  --mail-from "noreply@yourco.com" \
  --mail-rcpt "customer@example.com" \
  --user "noreply@yourco.com:your-smtp-password" \
  --upload-file - <<EOF
From: Your Co <noreply@yourco.com>
To: customer@example.com
Subject: Welcome!

Thanks for signing up.
EOF

Inbound Routing

Receive mail at any address on your domain and have it delivered to your server as a structured webhook. Perfect for reply-tracking, customer-support ingestion, and automated workflows.

How it works

1. Point your domain's MX record to mail.maildog.io (already done if you followed the Quickstart).
2. Create an inbound address in Panel → Inbound → Email Addresses and set its Webhook URL.
3. Optionally, bind a whole custom domain to the address so any localpart (support@,bong@, feedback@) routes to the same webhook.
4. When an email arrives, MailDog parses the headers and body, uploads large attachments to storage, and POSTs a JSON payload to your webhook.

Webhook payload

{
  "id": 12345,
  "sender": "customer@example.com",
  "recipient": "support@yourco.com",
  "subject": "Issue with invoice",
  "message_id": "<abc123@example.com>",
  "headers": {
    "From": "Customer <customer@example.com>",
    "To": "support@yourco.com",
    "Subject": "Issue with invoice",
    "Date": "Wed, 15 Apr 2026 09:00:00 +0000",
    "_envelope": {
      "helo_domain": "mail.example.com",
      "remote_ip": "203.0.113.45",
      "tls": true
    }
  },
  "plain_body": "Hi team, my invoice shows the wrong amount...",
  "html_body": "<p>Hi team, my invoice shows the wrong amount...</p>",
  "attachments": [
    {
      "filename": "invoice.pdf",
      "content_type": "application/pdf",
      "size": 48392,
      "url": "https://maildog-attachments.s3.amazonaws.com/..."
    }
  ]
}

Retries and replay

MailDog retries failed webhook deliveries with exponential backoff for up to 24 hours. Every message is stored in your inbound log so you can replay failed deliveries manually from the panel at any time.

Sandbox Testing

Sandbox inboxes are isolated SMTP endpoints for development. Point your app at a sandbox and every message is captured but never delivered to the outside world — perfect for CI, staging, and local dev.

Create a sandbox

Go to Panel → SMTP Sandboxes → New, give it a name, and you're done. Credentials are generated for you.

Hosted Webmail

Create full IMAP mailboxes for your domain and access them through a built-in web client. Good for team inboxes (support@, sales@) without paying Google Workspace per seat.

Mailboxes live at Panel → Webmail. Each account supports IMAP, POP3, and SMTP on the same credentials, so you can also plug them into native clients like Apple Mail, Outlook, or Thunderbird.

SMTP Tester

The built-in SMTP Tester is a diagnostic tool for debugging any SMTP server — MailDog or otherwise. It shows the full SMTP conversation in a live terminal: banner, EHLO capabilities, STARTTLS handshake, AUTH, MAIL FROM, RCPT TO, DATA, and the final queued response.

Use it when your application's email sends are failing and you need to know which step is broken — connectivity, TLS, auth, sender policy, or relay restrictions.

DNS & Security

Every domain you add to MailDog gets the same email-authentication stack the big senders use:

API Reference

Everything you can do in the panel is also available via the REST API. Authenticate with your API token in the Authorization header.

curl https://api.maildog.io/v1/domains \
  -H "Authorization: Bearer YOUR_API_TOKEN"

Common endpoints

Full API reference with schemas and examples is available on request — get in touch.

FAQ