Finds the domain name (PTR record) associated with an IP address; used for email server reputation and network diagnostics.
What Is Reverse DNS (PTR)?
While normal DNS resolves a domain name to an IP, reverse DNS resolves an IP address to a host name. This is done through the PTR record defined by the network that owns the IP, and it is stored in the in-addr.arpa zone.
Why Does It Matter?
Reverse DNS is especially critical for email servers. Many receiving servers expect the sending IP to have a valid and consistent PTR record; a missing or mismatched PTR can cause your emails to be flagged as spam.
How to Use It
- Enter the IP address you want to look up (e.g.
8.8.8.8). - View the host name assigned to the IP.
Tip: If you run your own mail server, make sure your PTR record is consistent with your sending domain. This record is usually configured by the hosting provider that supplies the IP.
Frequently Asked Questions
Who sets up the PTR record?
The owner of the IP block, namely your hosting provider or data center. It is defined in the authoritative zone of the IP, not in your own domain.
What happens if there is no PTR record?
It is not a problem for websites, but your deliverability may suffer when sending email.
