---
title: Set up an email sending domain in Infinity3
description: "Authenticate a dedicated sending domain for marketing emails sent through the platform’s built-in email service. #### Before you start You’ll need email-settings access and help from whoever manages your domain’s DNS. This process applies to the built-in sending service; an…"
url: "https://www.infinity3.co.uk/help/set-up-an-email-sending-domain-in-infinity3/"
updated: "2026-10-08"
category: Infinity3 Platform / Email Marketing
---

# Set up an email sending domain in Infinity3

Authenticate a dedicated sending domain for marketing emails sent through the platform’s built-in email service.

#### Before you start

You’ll need email-settings access and help from whoever manages your domain’s DNS. This process applies to the built-in sending service; an external SMTP provider may require different setup.

Choose an unused subdomain, such as mail.example.co.uk. If your main domain already handles business email, use a separate subdomain to avoid conflicting with its existing mail settings.

#### Add the domain

1. Log into [app.infinity3.ai](https://app.infinity3.ai).
2. Open **Settings** → **Email Services**.
3. Open **Dedicated Domain** or **Dedicated Domain and IP**.
4. Select **Add Domain**, enter the chosen subdomain and continue.
5. Use the supported automatic DNS setup where available, or give the displayed records to your DNS administrator.
6. Add the exact record types, names and values supplied by Infinity3.
7. Return to email settings and run verification.

#### Check before sending

Review domain verification, the campaign sender configuration and the reply-to address. Send a sample campaign to an external test address.

#### Things to know

- Connecting Gmail or Outlook does not complete marketing-domain setup.
- Do not replace unrelated website or business-mail DNS records.
- A dedicated domain is different from a dedicated IP address.
- Build sending volume gradually with an appropriate, permission-based audience.

If setup is unclear, contact Infinity3 with the chosen subdomain and DNS provider before making changes.