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

# Set Up Reverse DNS (PTR) for Dedicated IP Reputation

> Learn how rDNS works, why it matters for dedicated IPs, and how to request a custom PTR record from mySMTP. Check rDNS with dig, nslookup, or the Toolbox.

Reverse DNS (rDNS) helps receiving servers verify that your sending IP matches your domain name. Forward-confirmed rDNS reduces the chance that your mail is rejected or filtered as suspicious.

## What is PTR/rDNS

A PTR record maps an IP address back to a hostname. It is the reverse of a regular DNS A record, which maps a hostname to an IP. Receiving mail servers often check that the IP sending them mail has a valid PTR record, and that the hostname it resolves to points back to the same IP (forward-confirmed rDNS).

## Why receivers check rDNS

Mailbox providers and spam filters use rDNS as a basic trust signal:

* IPs without PTR records may be treated as less reputable.
* Mismatched forward and reverse DNS looks like spoofing or misconfiguration.
* Some receivers reject mail outright from IPs that fail this check.

## Who sets the PTR record

The owner of the IP address controls PTR records. Because mySMTP owns the IP addresses allocated to your account, **mySMTP sets and manages PTR records for all dedicated IPs**. You cannot add a PTR record at your own DNS provider.

If you need a custom PTR name for your dedicated IP (for example, to match your sending domain), contact [support@mysmtp.com](mailto:support@mysmtp.com) with your request.

<Note>
  Shared IP plans are only available to customers in Denmark. PTR for shared IPs is managed by mySMTP and cannot be customized.
</Note>

## How to check your current PTR

You can verify the current PTR record for your IP using any of these methods.

<Tabs>
  <Tab title="dig">
    Run this command, replacing `YOUR_IP` with your sending IP:

    ```bash theme={null}
    dig -x YOUR_IP +short
    ```

    Example output:

    ```text theme={null}
    relayxx.mysmtp.com.
    ```
  </Tab>

  <Tab title="nslookup">
    Run this command, replacing `YOUR_IP` with your sending IP:

    ```bash theme={null}
    nslookup YOUR_IP
    ```

    Look for the "name" line in the response.
  </Tab>

  <Tab title="Toolbox">
    Use the rDNS checker in the [mySMTP Deliverability Toolbox](https://toolbox.smtp.ai/) to look up PTR records without installing tools.
  </Tab>
</Tabs>

<Warning>
  Always use the hostname from your setup email. `relayxx.mysmtp.com` is an example. Shared IP (DK only) customers use `mail.mysmtp.com`.
</Warning>

## Shared IP (DK only) behavior

On shared IP plans, the PTR record is set by mySMTP to a shared hostname. Individual customers cannot request custom PTR names on shared IPs. If you require a custom PTR, consider upgrading to a dedicated IP plan.

## Related articles

* [SPF, DKIM, DMARC, and BIMI explained](/deliverability/spf-dkim-dmarc-and-bimi-explained)
* [DNS setup for authentication](/deliverability/dns-setup-for-authentication)
* [IP reputation: dedicated vs shared IPs](/deliverability/ip-reputation-dedicated-vs-shared-ips)


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