Reverse DNS lookup is a process by which the IP address of a client is matched to the domain space the client claims to come from. Reverse DNS is i mplemented in the DNS in-addr.arpa zone and can be used, among other things, to verify that an e-mail message came from the apparent sender named in the message. If the IP address of the sender does not match the DNS zone information for the sender's domain name, or if the information cannot be verified because the lookup information doesn't exist, the lookup will fail and the service request will be rejected.

Updated On: 04.03.26