Reverse DNS (PTR)
Look up the hostname assigned to an IP address in reverse DNS, and check whether that hostname points back to the same address.
About this tool
Forward DNS resolves a name to an IP address. Reverse DNS works the other way and shows the hostname assigned to an IP address. That hostname is stored in a PTR record.
Reverse DNS matters most for email servers. Receiving servers check that the sender's IP address has a PTR record and that the hostname in turn points back to the same IP. Without this, email is likely to be marked as spam or rejected.
The PTR record is managed by whoever owns the IP address — usually the hosting provider or internet service provider. It is not part of your domain's DNS zone.
Frequently asked questions
How do I change the PTR record for my server?
Contact whoever provides the IP address. If you have a VPS or server with Admax, our support team can sort it out for you.
What does it mean for the hostname to point back?
It means the hostname in the PTR record has an A or AAAA record with the same IP address. This is called forward-confirmed reverse DNS, and it's what email servers verify.
Does a web server need reverse DNS?
No, visitors aren't affected. It's mainly servers that send email that need a correct PTR record.