What is a PTR record?
Learn what PTR records are, how reverse DNS works, and why PTR validation matters for email systems.
What a PTR record does
A PTR record is used for reverse DNS. Instead of mapping a name to an address, it maps an IP address back to a hostname.
This is commonly used in email environments where receiving systems may check reverse DNS as part of reputation or validation logic.
Why PTR matters
A missing or badly configured PTR record can affect deliverability and trust for outbound mail systems.
It is especially important that reverse DNS and forward DNS line up sensibly for mail servers.
What to validate
- Whether the IP has a PTR record at all
- Whether the PTR target resolves forward
- Whether the forward result includes the original IP