Reverse DNS Lookup

Reverse lookups are commonly used by email servers. Email servers check and see if an email message came from a valid server before bringing it onto their network. Many email servers will reject messages from any server that does not support reverse lookups or from a server that is highly unlikely to be legitimate. Spammers often use IP addresses from hijacked machines, which means there will be no PTR record. Or, they may use dynamically assigned IP addresses that lead to server domains with highly generic names.
Logging software also employs reverse lookups in order to provide users with human-readable domains in their log data, as opposed to a bunch of numeric IP addresses.

Reverse DNS Lookup works by querying a DNS server to find the hostname that corresponds to a given IP address. The DNS server looks up the IP address's reverse DNS record and returns the associated hostname.

Reverse DNS Lookup differs from regular DNS Lookup in that it retrieves the hostname associated with a given IP address, whereas regular DNS Lookup retrieves the IP address associated with a given hostname.

Yes, Reverse DNS Lookup can be used to detect spam. This is due to the fact that many spammers use bogus or illegitimate domain names in their email addresses. You can determine whether a domain name is legitimate or not by performing a Reverse DNS Lookup on the IP address associated with the email.

There are no significant risks to using Reverse DNS Lookup. However, it is critical to use trustworthy tools and websites for the lookup, as well as to have up-to-date antivirus software installed on your device.

The PTR record is used for reverse DNS lookups.