Reverse DNS (PTR)
Find the hostname an IP address resolves back to.
How this lookup works
Forward DNS turns a name into an address; reverse DNS does the opposite, using a PTR record. Enter an IP and this tool queries the PTR record that its owner has published, if any.
What the results mean
- PTR hostname
- The name the address’s owner has assigned to it. For a mail server this usually matches its forward record, which receiving servers check.
- No PTR record
- The address has no reverse record. Common for home and mobile connections, and not a problem unless the address is being used to send mail.
Frequently asked questions
Why does reverse DNS matter for email?
Receiving mail servers often reject or distrust mail from an address whose PTR record is missing or does not match its forward hostname. It is a basic signal of a legitimately-run mail server, which is why hosting providers let you set it.
Can I set the reverse record for my home IP?
Usually not — it is controlled by your ISP, who owns the address. On a server or hosting account you typically can, through the provider’s control panel.