How to Configure Reverse DNS on a Virtuozzo VPS (Step by Step)

If your VPS sends email, a missing or wrong reverse DNS record is one of the fastest ways to land in spam folders. On a Virtuozzo VPS, there is a twist: you can't create the record from inside the server. This guide shows you exactly who controls it, what to set, and how to check it works.

What reverse DNS actually does

Normal DNS turns a name into an IP address. Reverse DNS does the opposite: it turns an IP back into a name. It uses a PTR record stored in a special zone, such as in-addr.arpa for IPv4.

Mail servers check it constantly. If your IP 203.0.113.25 points back to mail.example.com, and that name points to the same IP, receivers trust you more. This match is called forward-confirmed reverse DNS (FCrDNS).

Cloudflare has a clear explainer on how PTR records work if you want the background.

Why Virtuozzo users can't set reverse DNS themselves

Virtuozzo is the virtualization layer. It runs your container or VM, but it does not manage DNS for IP addresses. The PTR zone belongs to whoever owns the IP block, which is your hosting provider.

So the workflow always has two parts:

• You set a proper hostname and a matching forward (A) record.
• Your provider creates the PTR record, either through a panel field or a support ticket.

Step-by-step: configure reverse DNS on a Virtuozzo VPS

Step 1: Pick a fully qualified hostname

Choose a name you control, such as mail.example.com or server1.example.com. Avoid bare names like localhost or vps123.

If you are sending mail, use the same name your mail server announces in its HELO/EHLO greeting.

Step 2: Create the forward A record first

In your domain's DNS zone, add an A record pointing the hostname to your VPS IP. Our guide to pointing your domain to your VPS covers this in detail.

Providers often refuse a PTR request until the A record resolves, so do this first.

Step 3: Set the Virtuozzo VPS hostname

This is where Virtuozzo containers differ from regular servers. The host node manages some container files, so a hostname set only inside the container can revert after a reboot.

The safest option is to change the hostname in your VPS control panel, if it offers that setting. Then confirm it over SSH (see connecting to your server with SSH):

hostname -f
cat /etc/hostname

If your panel has no hostname option, set it from the shell and reboot to test that it sticks:

sudo hostnamectl set-hostname mail.example.com
sudo reboot

For reference, a Virtuozzo host administrator would use prlctl set <CT_ID> --hostname mail.example.com. You won't have host access on a hosted VPS, but it explains why panel changes are more permanent.

Step 4: Request the PTR record

Look in your client area for a field labelled rDNS, Reverse DNS or PTR. If there is none, open a support ticket with:

• Your VPS IP address (IPv4 and IPv6 if you use both)
• The exact hostname you want, e.g. mail.example.com
• Confirmation that the A record already resolves

The help centre is the place to start if you are hosting with us.

Step 5: Verify with an rDNS lookup

PTR changes can take some time to propagate. Then run an rDNS lookup from any Linux machine:

dig -x 203.0.113.25 +short
# expected: mail.example.com.

dig mail.example.com A +short
# expected: 203.0.113.25

You can also use host 203.0.113.25. Both lookups must agree for FCrDNS to pass.

Reverse DNS checklist for mail server deliverability

Run through this list before you send your first campaign:

• Hostname is a fully qualified domain name you own
• A (and AAAA) record points to the VPS IP
• PTR record returns the same hostname
• Mail server HELO/EHLO uses that hostname
• SPF, DKIM and DMARC records are published
• IPv6 has its own PTR, or IPv6 sending is disabled

In Postfix, the HELO name comes from myhostname:

sudo postconf -e 'myhostname = mail.example.com'
sudo systemctl reload postfix

Common problems and quick fixes

Next steps

Reverse DNS takes five minutes once you know the order: hostname, A record, PTR request, then verification. Get it right and your mail server starts with a clean reputation.

Planning a new mail or app server? A spidra.cloud Cloud VPS starts from ৳650/month, and our team can help with PTR requests through the help centre.