n8n + MailKite

n8n is an open-source workflow automation platform. Use MailKite as the email layer: send via the SMTP node, receive inbound email via the Webhook trigger, and build email automation flows that connect to anything.

What you need

• A verified domain with SPF + DKIM published
• Your API key (mk_live_…)
• n8n instance (self-hosted or cloud)

Send email via SMTP node

In your n8n workflow, add an SMTP Send node. Configure it with MailKite's connection details:

# n8n SMTP Node settings
Host:     smtp.mailkite.dev
Port:     587
User:     mailkite
Password: mk_live_...
SSL/TLS:  true (STARTTLS)
From:     notifications@yourdomain.com

The SMTP node sends plain text or HTML email. Map the To, Subject, and Text/HTML fields from previous nodes in your workflow.

Receive inbound email via Webhook trigger

Add a Webhook node as your workflow trigger. Set it to POST and copy the URL into your MailKite domain's webhook settings. Every inbound email fires the workflow with this payload:

• from — sender address
• to — recipient address
• subject — email subject
• text — plain text body
• html — HTML body
• attachments — array of file objects

Example workflow

A common pattern: filter inbound email, process it, and send an auto-reply:

// n8n workflow: Inbound email → Process → Reply
//
// 1. Webhook node (trigger)
//    - Method: POST
//    - Path: /mailkite-inbound
//    - Receives: { from, to, subject, text, html, attachments }
//
// 2. IF node — filter
//    - Condition: subject contains "support"
//    - True → continue
//    - False → Respond (200 OK, skip)
//
// 3. Code node — process
//    - Extract ticket info from subject/body
//    - Create record in your database
//
// 4. SMTP node — send reply
//    - To: {{ $json.from }}
//    - Subject: Re: {{ $json.subject }}
//    - Text: Thanks for reaching out. We'll get back to you within 24 hours.
//
// 5. Respond to Webhook node
//    - Status: 200
//    - Body: { "ok": true }

Test it

# Trigger the n8n webhook manually
curl -X POST https://your-n8n.example.com/webhook/mailkite-inbound \
  -H "Content-Type: application/json" \
  -d '{
    "from": "customer@example.com",
    "to": "support@yourdomain.com",
    "subject": "Need help with my order",
    "text": "Hi, I placed order #1234 but haven't received it yet."
  }'

Self-hosted n8n

If you run n8n on your own infrastructure, set the webhook URL to your n8n instance's public URL. MailKite must be able to reach it — use a tunnel (ngrok, Cloudflare Tunnel) if n8n is behind a firewall.

Troubleshooting

• SMTP node timeout — ensure you're on port 587 with TLS. Port 25 is blocked by most networks.
• Webhook not firing — the webhook must be active (toggle it on in n8n). Send a test email after activating.
• Missing fields — n8n's Webhook node returns the full MailKite payload. If a field is missing, check the raw body in the Webhook node's output.
• n8n behind firewall — use npx localtunnel --port 5678 or Cloudflare Tunnel to expose the webhook.

See the SMTP relay docs for connection details, or Inbound webhooks for the full payload.