---
title: "Required DNS settings for Opensense"
slug: "dns-entries-must-have"
description: "The two DNS records every Opensense customer needs: a smart CNAME record pointing to whs.sendergen.com, and include:_spf.sendergen.com in your SPF record."
updated: 2025-09-05T14:56:53.000Z
canonical: "https://help.opensense.com/docs/dns-entries-must-have"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.opensense.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Required DNS settings for Opensense

## Overview

To make sure email branding and deliverability work properly, every Opensense customer must configure two DNS records: a new CNAME record, and an update to the existing SPF record. If you use Cloudflare, see [Setting up the Opensense CNAME in Cloudflare](https://help.opensense.com/docs/cname-cloudflare-proxy-settings) before you add the CNAME record.

:::caution[External and internal DNS]
Apply these updates to your **external** DNS and, if applicable, your **internal DNS** too.
:::


## Why these records matter

- Consistent and secure brand presentation across emails
- Better email deliverability and authentication alignment
- Support for Opensense's email signature and tracking infrastructure


## DNS records required by Opensense

<div class="kb-deployment-compare kb-deployment-compare--plain">
  <div class="kb-deployment-compare__viewport" role="region" aria-label="DNS records required by Opensense" tabindex="0">
    <table>
      <colgroup><col class="kb-deployment-compare__feature-col"></colgroup>
      <thead>
        <tr>
          <th scope="col">Setting</th>
          <th scope="col"><span class="kb-deployment-compare__method">1. CNAME record</span></th>
          <th scope="col"><span class="kb-deployment-compare__method">2. SPF record</span></th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <th scope="row">Action</th>
          <td>Create a new record</td>
          <td>Modify your existing TXT record</td>
        </tr>
        <tr>
          <th scope="row">Record type</th>
          <td>CNAME</td>
          <td>TXT (SPF)</td>
        </tr>
        <tr>
          <th scope="row">Host or name</th>
          <td><code>smart</code></td>
          <td><code>@</code> or your domain root (for example, <code>customer.com</code>)</td>
        </tr>
        <tr>
          <th scope="row">Value<span class="kb-deployment-compare__row-note">Points to, FQDN, or target</span></th>
          <td><code>whs.sendergen.com</code></td>
          <td>Add <code>include:_spf.sendergen.com</code></td>
        </tr>
        <tr>
          <th scope="row">Example</th>
          <td><span aria-hidden="true">—</span><span class="sr-only">None</span></td>
          <td><code>v=spf1 include:_spf.google.com include:_spf.sendergen.com ~all</code></td>
        </tr>
      </tbody>
    </table>
  </div>
</div>

## Updating your SPF record

1. Find your current SPF TXT record. It usually begins with `v=spf1`.
2. Add this include statement to the existing entry:

```plaintext
include:_spf.sendergen.com
```

The underscore in `_spf.sendergen.com` is **critical**. Make sure that it isn't left out.

:::caution[Only one SPF record]
Don't create a separate SPF record. There must be only one **v=spf1** TXT record at the root level of each domain.
:::


## What's next

- [Verifying your Opensense DNS records](https://help.opensense.com/docs/how-to-check-your-dns-records): check that the records are in place.
- [Setting up the Opensense CNAME in Cloudflare](https://help.opensense.com/docs/cname-cloudflare-proxy-settings)
- [Opensense SSL certificates from Let's Encrypt: CNAME and CAA requirements](https://help.opensense.com/docs/opensense-ssl-certificates-using-letsencrypt): if your domain uses CAA records.

For further help, contact Opensense Support at [help@opensense.com](mailto:help@opensense.com).