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# DNS Guide: Route 53 (AWS)

## Steps

1. Log in to the [AWS Management Console](https://console.aws.amazon.com)
2. Navigate to **Route 53**, then select **Hosted Zones**
3. Click on your domain's hosted zone
4. Click **Create Record** for each record PostNuvia requires

> **Note**
>
> If your domain is registered with a different registrar but uses Route 53 for DNS, make sure the NS records at your registrar match the name servers listed in your hosted zone.

## Adding a TXT Record (SPF)

| Field       | Value                                                |
| ----------- | ---------------------------------------------------- |
| Record name | Leave blank for root domain, or enter your subdomain |
| Record type | `TXT`                                                |
| Value       | `"v=spf1 include:postnuvia.com ~all"`                 |
| TTL         | `300`                                                |

> **Warning**
>
> Route 53 requires TXT values to be **wrapped in double quotes**. If you omit the quotes, the record will fail validation. Also, if you already have an SPF record, add `include:postnuvia.com` to the existing record rather than creating a second one. Multiple SPF records on the same domain will cause authentication failures.

## Adding a TXT Record (DKIM)

| Field       | Value                                                               |
| ----------- | ------------------------------------------------------------------- |
| Record name | The DKIM selector host from PostNuvia (e.g., `selector._domainkey`) |
| Record type | `TXT`                                                               |
| Value       | The quoted DKIM TXT value from PostNuvia                            |
| TTL         | `300`                                                               |

Route 53 requires TXT values to be **wrapped in double quotes**. If a DKIM TXT value is longer than 255 characters, split it into adjacent quoted strings within one TXT record.

> **Note**
>
> Legacy orgs should keep existing working DNS records in place. For new domain setup, add the TXT selector records shown in PostNuvia.

## Adding an MX Record (Receiving)

| Field       | Value                                                |
| ----------- | ---------------------------------------------------- |
| Record name | Leave blank for root domain, or enter your subdomain |
| Record type | `MX`                                                 |
| Value       | `10 inbound.postnuvia.com`                            |
| TTL         | `300`                                                |

Route 53 MX records use the format `priority server` separated by a space (e.g., `10 inbound.postnuvia.com`). Do not wrap MX values in quotes.

If you want to receive emails on a subdomain to avoid conflicts with your existing email provider, enter the subdomain in the Record name field instead of leaving it blank.

## Verification

After adding all records, go back to the [PostNuvia Console](https://console.postnuvia.com) and click **Verify Domain**.

Route 53 name servers typically pick up changes within **60 seconds**, but full propagation to all DNS resolvers may take longer depending on TTL and resolver caching. In practice, most changes are visible within a few minutes.

## Common Route 53 Issues

* **TXT records must be quoted:** Unlike most DNS providers, Route 53 requires double quotes around TXT record values. If your SPF, DKIM, or DMARC TXT records are missing quotes, they won't validate.

* **Existing SPF record:** If you already have a TXT record starting with `v=spf1`, add `include:postnuvia.com` before the `~all` or `-all` in that existing record. Do not create a second SPF TXT record.

* **Routing policy:** When creating records, use **Simple routing** unless you have a specific reason to use weighted, latency, or other routing policies. Other policies can cause unexpected DNS behavior for email records.

* **Multiple values in one record:** Route 53 lets you add multiple values to a single record. If you need to add a second MX entry, add it as a new line in the same MX record rather than creating a separate record.

* **DKIM TXT record too long (CharacterStringTooLong error):** DKIM public keys are often longer than the 255-character limit that Route 53 enforces per string segment. You will see an error like `CharacterStringTooLong (Value is too long)`. To fix this, split the value into two quoted strings within a single record. The split point should be near the middle of the `p=` value. The two quoted strings must have **no space and no line break** between the closing and opening quotes. For example:

  ```
  "v=DKIM1; k=rsa; p=MIIBIjANBgkqhki...firsthalf""secondhalf...wIDAQAB"
  ```

  In Route 53, paste the entire value (both quoted strings) into the **Value** field as a single entry. If Route 53 shows two separate copy-pastable values instead of one, there is likely a space or line break between the two strings. Remove it so the closing `"` and opening `"` are directly adjacent (`""`).

  **Incorrect:** A space or line break between the two quoted strings causes Route 53 to treat them as separate values.

  ![Incorrect Route 53 DKIM configuration with space between quoted strings](/_fern-img/5145d22514b03251934e96ef49b78f8ca79e6b20bfa7ec5065a343ac547338e9.webp)

  **Correct:** The two quoted strings are directly adjacent with no space, producing a single value in Route 53.

  ![Correct Route 53 DKIM configuration with no space between quoted strings](/_fern-img/d67b72b3e23c286ef81bb101c57098bab684785fca4bf3791fd7f0fffe864740.webp)

  You can also use the AWS CLI to add the record, which handles multi-string TXT values more reliably.