[ Free tool · Reputation & Security ]

Reverse DNS (PTR) Checker

Check PTR records and forward-confirmed reverse DNS for sending IPs.

[ About this tool ]

This reverse DNS checker looks up the PTR record for a sending IP, or for every mail server of a domain, and confirms the hostname resolves back to the same IP (forward-confirmed reverse DNS).

How to read the results

  • ›Every sending IP needs exactly one PTR record.
  • ›The PTR hostname must resolve back to the same IP (FCrDNS).
  • ›Generic hostnames such as 1-2-3-4.isp.net look like home connections to spam filters.

Frequently asked questions

Why does reverse DNS matter for email?

Gmail, Yahoo and Microsoft require sending IPs to have valid forward-confirmed reverse DNS. Mail from IPs without it is often rejected or sent to spam.

Who sets the PTR record?

The owner of the IP address, usually your hosting or email provider, not your DNS host.

Learn more in our guide: Email Deliverability: How to Reach the Inbox, Not Spam

Enterprise provenance

Why top financial institutions and governments retired their email security dashboards.

Traditional email authentication platforms sell you a dashboard and ask your engineers to do the labour. In high-stakes environments, manual oversight means delayed enforcement, configuration drift and unmonitored shadow domains.

EmailAuth is the agentic email provenance platform. Our agents enforce p=reject, keep third-party senders aligned and move your domains to full RFC 9989 compliance, the new DMARC standard,, with human-in-the-loop auditability.

Governments Large enterprises Tier-1 financial institutions

SaaS · Dedicated tenancy · Air-gapped on-prem · BYOK encryption

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