Reverse DNS (rDNS)
What reverse DNS is and how to configure it for your IP
What is Reverse DNS?
Reverse DNS (rDNS or PTR record) does the opposite of normal DNS: instead of translating a name to an IP, it translates an IP to a hostname.
It's especially important for servers that send email: many mail servers reject emails if the sender doesn't have a correctly configured PTR record.
How to Check the Current PTR Record
# From the server
host SERVER_IP
# With dig
dig -x SERVER_IP
# With nslookup
nslookup SERVER_IPHow to Configure Reverse DNS
The PTR record is managed by the IP provider (that's us), not by your domain registrar.
To configure it:
- Access your client panel
- Select your server or your IP
- Look for the Reverse DNS or PTR Record section
- Enter the desired hostname (e.g.,
mail.example.com) - Save
The name you enter in the PTR must correspond to an A record pointing to your server's IP. In other words, mail.example.com must resolve to your server's IP.
Recommended Configuration for Email Sending
If your server sends email, configure the PTR so it matches your mail server's hostname. Example:
- Server IP:
1.2.3.4 - PTR record:
mail.example.com - A Record:
mail.example.com→1.2.3.4
Email Configuration Verification
You can test whether your IP is blacklisted or your PTR is correct with these tools:
- MXToolbox: blacklist and PTR check
- mail-tester.com: comprehensive email configuration test