---
title: "Add a DKIM record at one.com, plus SPF and DMARC"
date: "2026-11-06"
author: RocketCart
url: "https://getrocketcart.com/docs/sending-domain/one-com/"
type: docs
---

To send RocketCart emails from a one.com domain, add three TXT records under **DNS records** in the one.com Control Panel.

## The records RocketCart needs

| Record | Type | Hostname | Value |
| --- | --- | --- | --- |
| SPF | TXT | empty | `v=spf1 include:mailgun.org ~all` |
| DKIM | TXT | `<selector>._domainkey` | `v=DKIM1; k=rsa; p=<your public key>` |
| DMARC | TXT | `_dmarc` | `v=DMARC1; p=none` |

- Copy every value from the **DNS records** panel in RocketCart (**Settings > Email Settings**). Click **Copy value** on each tab. `<selector>` and `<your public key>` are unique to your store. If the app shows the literal word `<selector>` in Host/Name, your selector is your store name as RocketCart saved it on install: lowercase letters and numbers, hyphens between words, for example `my-store` for “My Store”.
- one.com adds your domain to the hostname. Leave it empty for the domain itself, and type only the prefix for the others.

## How do I add a TXT record at one.com?

1. Log in to the one.com Control Panel.
2. On the **Advanced settings** tile, select **DNS settings**.
3. Go to **DNS records**.
4. Under **Create new record**, choose **TXT**.
5. In the hostname field, enter the prefix from the table, or leave it empty for the SPF record.
6. In **Value**, paste the value you copied from RocketCart.
7. Leave **TTL** empty to use the default of 3600 seconds.
8. Click **Create record**.
9. Repeat for the other two records.

Warning

Records only work where your domain’s DNS is managed. If your domain’s nameservers point to another company (for example your web host), add the records there instead.

## What if I already have an SPF record?

A domain can only have one SPF record. With two, both fail. If you already have a TXT record that starts with `v=spf1`, edit that one instead of adding a new one. Put `include:mailgun.org` **before** the `~all` or `-all` at the end:

|  | Value |
| --- | --- |
| Your record now | `v=spf1 include:_custspf.one.com ~all` |
| After your edit | `v=spf1 include:_custspf.one.com include:mailgun.org ~all` |

Keep every service your record already lists. Only add `include:mailgun.org`.

Mail servers stop reading an SPF record at `~all` or `-all`, so an include placed after it is ignored. If the value RocketCart suggests ends with `include:mailgun.org`, move that part in front of `~all` when you paste it.

If you use one.com email, your domain probably has the first record already. Edit it rather than creating a second SPF record.

## What if I already have a DMARC record?

Keep it and skip the DMARC record. A domain should have only one DMARC record on `_dmarc`, and RocketCart accepts any valid one.

## Verify the records in RocketCart

1. In RocketCart, go to **Settings > Email Settings**.
2. In the **DNS records** panel, click **Verify DNS**.
3. When all three tabs show **Verified** (**Status: 3/3 DNS records verified.**), turn on **Enable custom domain**.

one.com says a change can take up to 90 minutes to become active. RocketCart only checks when you click **Verify DNS**, so click it again later if a record still shows **Missing**. The full flow is in [Set up a custom sending domain](/docs/sending-domain/set-up-sending-domain/). If a record won’t verify, see [Sending domain not verifying](/docs/troubleshooting/sending-domain-not-verifying/).