Look up reverse DNS (PTR) records for any IP address to verify its hostname mapping.
1. Enter an IPv4 address (e.g., 8.8.8.8) or IPv6 address in the input field
2. Select your preferred DNS resolver (Google, Cloudflare, OpenDNS, etc)
3. Click “Lookup PTR Record” or press Enter
4. Review your results, including:
Understanding your results helps you diagnose and fix email delivery issues faster.
PTR Hostname
The domain name mapped to your IP address. This is what receiving mail servers see when they perform a reverse DNS lookup on your sending IP.
TTL (Time to Live)
Indicates how long (in seconds) DNS resolvers cache your PTR record.
FCrDNS (Forward-Confirmed Reverse DNS)
Our tool verifies whether your PTR hostname resolves back to the same IP address using a forward lookup.
Deliverability Checks
We run multiple checks to evaluate your reverse DNS setup:
| Check | What It Means |
| PTR Record Exists | Confirms a reverse DNS entry is configured |
| FCrDNS Match | Ensures hostname resolves back to the same IP |
| Hostname Pattern | Checks if hostname resembles a legitimate mail server (e.g., contains "mail", "smtp", "mx") |
Based on all checks, you’ll receive a clear status:
PTR Record Valid & Verified
Reverse DNS is correctly configured with FCrDNS confirmed
PTR Found – Warnings Present
PTR exists, but improvements are needed
PTR Issue Detected / No PTR Record Found
Likely causing email deliverability problems
A PTR (Pointer) record maps an IP address to a domain name. It’s the reverse of an A record and is used in reverse DNS lookups.
Reverse DNS lookup resolves an IP address back to its associated domain name, helping servers verify sender identity.
FCRDNS stands for Forward-Confirmed Reverse DNS. It’s a method used to verify that an IP address and its domain name are properly and consistently mapped, which is especially important in email authentication and spam filtering.
A PTR record checker is a tool that performs a reverse DNS lookup and validates whether your PTR record is correctly configured.
Without a PTR record:
Your PTR record is controlled by the organization that owns your IP address, typically your hosting provider, ISP, or cloud service provider.
An A record maps a domain name to an IP, while a PTR record does exactly the opposite – it maps an IP address back to its domain name. You can view it as looking up a contact number for an A record, and reverse-searching a number to find out who it belongs to for a PTR record.
Yes. A valid PTR record with FCrDNS alignment is a critical factor in email deliverability and spam filtering decisions, and hence, a missing record can potentially harm deliverability.
