Reverse DNS records are engineered to maintain consistency between a web site or service which runs on a specific IP address when performing DNS lookups.
Typically, these are most common with mail servers, specifically hostnames. When one mail server attempts to communicate with another, the receiving mail server will be given the IP address and hostname of the sending mail server to identify it. The first thing the receiving mail server will do is perform a Reverse DNS lookup on the IP address of the sending mail server to see if the Hostname matches the Reverse DNS record. This is done to verify the validity of the sending mail server.
If the Hostname and Reverse DNS record do not match, there is a higher chance the message will either be mistaken as a spam message and marked as such upon delivery, or simply returned to the sending mail server.
For our Hosted Email and Legacy Shared Mail servers, the Hostname and Reverse DNS are automatically configured for the most optimal settings.
For our Public Cloud Hosted Email Services, the Hostname and Reverse DNS are also automatically configured for optimal settings.
For all Dedicated and Private Cloud server customers, any request for a specific Reverse DNS entry must be made via submission of a support ticket, and we do apologize for any inconvenience.
If you have any further questions regarding Reverse DNS lookups, please feel free to contact our Technical Support Department for more information.