Reverse DNS Lookup

Reverse DNS lookup — resolving an IP address back to its associated hostname — is essential for network security investigations, email deliverability configuration, and server identity verification. Many enterprise email spam filters perform a reverse DNS check on the sending IP address to verify that a PTR record exists and that it matches the forward DNS record. Without a properly configured PTR record, legitimate emails from your mail server may be flagged as spam or rejected outright.

The Reverse DNS Lookup tool resolves any IPv4 or IPv6 address to its associated hostnames using PTR record queries, and enriches the results with hosting provider and organization information. Use it to identify which domains or services are hosted on a given IP address, verify that your mail server's PTR record is properly configured, or investigate suspicious IPs found in server logs or network traffic. The hosting provider context helps you quickly determine whether an IP belongs to a major cloud provider, CDN, or hosting company.