Reverse DNS maps an IP to a name
PTR records are published in reverse address zones: in-addr.arpa for IPv4 and ip6.arpa for IPv6. Mail receivers often compare reverse DNS with forward address records.
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PTR lookup
Look up reverse DNS for an IP address and inspect forward confirmation.
Your result will appear here.
Run the check to see structured findings, severity, evidence and next steps from the public diagnostics API.
The details
Reverse DNS maps an IP to a name
Forward confirmation is useful context
A PTR answer alone does not prove a host is authorized to send mail. Forward-confirmed reverse DNS means the returned hostname resolves back to the original address.
A result is a point-in-time check
DNS can vary by resolver and change over time. Verify important changes with your DNS provider and mail platform. Public DNS checks cannot see every private report or sending configuration.
Explore MailConfig ProFrequently asked questions
What does the PTR lookup do?
Look up reverse DNS for an IP address and inspect forward confirmation.
Do I need an account?
No. This public tool is available without registration.