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Reference · Glossary

PTR record

Pointer record (reverse DNS)

Definition

A record that turns an IP address back into a host name.

In plain words

Mail servers look up the sending address’s PTR record and check that the name points back to the same address. It is set by whoever holds the IP address, not among your domain’s records.

Why it matters to a firm

Gmail and Microsoft refuse or slow mail from a server without one, which catches mail sent straight from a web server or an office device.

The check behind the finding

nslookup 203.0.113.10

Run it on the sending address from a bounce. No name means no PTR record.

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