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

# Reverse DNS (PTR)

> Reverse record for your IP: why and how to get one

Reverse DNS (a reverse record, PTR) is an "IP address → name" binding. Regular DNS answers what IP `example.com` has. A PTR answers the reverse: what name `192.0.2.10` has.

## Why you need it

The main scenario is mail servers. When your server sends an email, the receiving side checks whether the name in the PTR matches what the server introduced itself as. If there's no PTR, or it doesn't match, the email will almost certainly land in spam or be rejected.

For a regular website, you don't need a PTR. It matters precisely when you're sending mail from your own server.

## How PTR differs from an A record

|                   | A record (forward)        | PTR record (reverse)                     |
| ----------------- | ------------------------- | ---------------------------------------- |
| What it describes | name → IP                 | IP → name                                |
| Who manages it    | you, in your domain's DNS | the owner of the IP block, i.e. the host |
| Where it lives    | at your DNS provider      | at Lumi                                  |

The key point: **you can't set a PTR yourself**. The reverse zone belongs to the owner of the address range — that is, the host. So a PTR is configured only on Lumi's side.

<Warning>
  There's no button for PTR in the @lumivps\_bot bot itself — a reverse record is configured only through support @lumisup\_robot.
</Warning>

## How to get one from Lumi

<Steps>
  <Step title="Prepare the A record">
    The domain whose name you want to see in the PTR must have a forward [A record](/en/domains/dns) pointing to this same IP. The name usually matches the mail server's name, for example `mail.example.com → 192.0.2.10`. Forward and reverse must point to each other.
  </Step>

  <Step title="Write to support">
    Open [@lumisup\_robot](https://t.me/lumisup_robot) and ask to set up a PTR. Include:

    * the server's IP address (it's on the VPS card in the bot);
    * the desired name (for example, `mail.example.com`).
  </Step>

  <Step title="Wait for confirmation">
    Support will add the record to the reverse zone. DNS changes can take up to a few hours to propagate around the world.
  </Step>
</Steps>

## Verification

Once it's set up, check the PTR with:

```bash theme={"system"}
dig -x 192.0.2.10 +short
```

The reply should show the name you specified (for example, `mail.example.com.`). If `dig` isn't installed, install it (`apt install dnsutils`) or use an online service like [mxtoolbox.com](https://mxtoolbox.com).

## Where to next

<CardGroup cols={1}>
  <Card title="SSL certificate" icon="lock" href="/en/vps/ssl">
    Free HTTPS via Let's Encrypt — the next step for a mail server.
  </Card>
</CardGroup>