Free DNS Tool

Reverse DNS / PTR Lookup

Check reverse DNS (PTR) records for any IP address. Essential for email deliverability and server configuration verification.

Quick lookup:

Understanding Reverse DNS

What is Reverse DNS?

Reverse DNS (rDNS) maps an IP address back to a hostname. It's the opposite of a regular DNS lookup, which maps hostnames to IPs.

PTR Records

PTR (Pointer) records are DNS records that store reverse DNS entries. They're managed by the IP address owner, typically your hosting provider.

FCrDNS

Forward-Confirmed Reverse DNS means the PTR hostname resolves back to the original IP. This is required by many email servers.

Pro Tip: If you're running a mail server, ensure your PTR record matches your server's HELO/EHLO hostname and that it resolves back to your IP. Use our Blacklist Checker to verify your sending IP's reputation.

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