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Connect your domain in 5 minutes

Send and receive email from your own domain, no matter where it is hosted. Unsendbox generates the exact DNS records you need and verifies them for you.

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How it works

For external mailbox setup, Unsendbox uses your Postmark server for outbound delivery and a protected inbound webhook for receiving. Add the DNS records, then apply the Postmark server settings below.

Works with any DNS host
GoDaddy, Namecheap, Route 53, Cloudflare, Google Domains: if you can edit DNS records, you can use Unsendbox.
Unsendbox tells you what to add
After you connect your domain, Unsendbox generates the exact MX, SPF, DKIM, and return-path records. Copy-paste them into your DNS provider.
One-click verification
Click Verify and Unsendbox checks your DNS in real time. Green across the board means you are ready to send.
What you need before starting
A Postmark server API token for outbound sending, access to the server Inbound stream settings, and a deployment administrator who can configure the webhook password. Never publish either token or password.

Step-by-step setup

From zero to verified domain in under 5 minutes.

  1. 01Create a Postmark server and copy its server API token. Keep the token private; Unsendbox uses it for outbound sending.
  2. 02In Unsendbox, go to Dashboard → Addresses → Domains and click Connect Domain.
  3. 03Enter your domain name, select SMTP Relay, and paste the Postmark server token.
  4. 04Add the 4 DNS records Unsendbox shows at your DNS provider, then click Verify.
  5. 05In Postmark Server → Inbound stream → Settings, set InboundHookUrl to https://app.unsendbox.com/api/v1/webhooks/inbound/postmark.
  6. 06Enable RawEmailEnabled for the Postmark server through the Servers API. The request requires a Postmark account token; the server token is not an account token.
  7. 07Protect the InboundHookUrl with HTTP Basic auth using username postmark and the deployment value of CLOUD_AWS_SECRET_EMAIL_INGEST_SECRET. Do not put the secret in public docs, screenshots, or source control.
  8. 08Send a test email. Unsendbox accepts the RawEmail field and the recipient from ToFull after authentication succeeds.

Already using Google Workspace?

Keep Google for your team email and add Unsendbox for AI agents. They work side by side without conflict.

Use a subdomain (recommended)
Run Unsendbox on mail.yourcompany.com while Google stays on yourcompany.com. Each has its own MX records, with zero interference.
Or forward specific addresses
Keep Google as your primary mail host. Set up Google routing rules to forward selected addresses to Unsendbox for AI processing.
Avoid loops
Forward in one direction only: Google → Unsendbox. Never mirror the same addresses back to Google.

Confirm everything works

Run through this checklist before going live.

  1. 01Domain status shows Active in Dashboard → Addresses → Domains.
  2. 02Domain health check passes for MX, SPF, and DKIM.
  3. 03Test address created and shows Active status.
  4. 04Outbound test email arrives in recipient inbox (not spam).
  5. 05Inbound test email appears in Unsendbox inbox.
  6. 06If using Google Workspace alongside, Google addresses still receive email normally.