Reverse DNS (PTR) Lookup — Free & Instant

About this tool. A PTR record maps an IP address back to a hostname — the reverse of an A record. Mail servers without matching forward and reverse DNS get their email rejected by many providers, so this is a must-check for any server that sends mail.

Ten signals decide whether your mail arrives. You just checked one.

Receiving servers distrust a sending IP with no PTR, or one whose PTR does not match forward. It is one of the oldest reputation signals still in use.

SPF, DKIM, DMARC, MX and blocklist status, graded A to F in one pass
Every problem written out in plain English, with the record to publish
Saved under Reports, so you can re-run it and see what changed
One domain watched against the blocklists daily

Run the full checkup free

No card, and nothing to cancel.

How to read your Reverse DNS (PTR) results

Reverse DNS (a PTR record) maps an IP address back to a hostname. Mail servers check it to judge sender legitimacy.
For a mail server, the PTR should resolve forward to the same IP (matching forward and reverse DNS).

Common problems and how to fix them

Your mail is treated as suspicious

Set a PTR record for your sending IP that matches your mail hostname, and make sure that hostname resolves back to the same IP. Your hosting provider sets the PTR, not your DNS host.

MX Lookup A Record AAAA Record CNAME Lookup Full email checkup

Common questions.

What is reverse DNS?

It is the lookup from an IP address to a hostname, using a PTR record, the opposite direction of a normal lookup.

Why does reverse DNS matter for email?

Receiving servers distrust senders whose IP has no PTR or whose PTR does not match. Matching forward and reverse DNS improves deliverability.