ReverseMX is built from two parts, the web site and a set of processes to crawl and process MX data.
The website is a Django web application which sits on top of a MySQL database. The main database tables with the mail server data are created by a periodic process using Hadoop, Hive, and a set of Python scripts.
Apart from the search and help pages, there are five main views of information in the ReverseMX site.
First on the home page we are displaying the popular mail servers based on how many domains specify them to handle their email. For each mail server we display the IP address, IP Location, Network Owner, number of Domains which use this mail server as well as an example Domain taken by finding the oldest. At the top of the page there is also an infographic displaying locations of the thousand most popular mail servers.
The Domain page gives Whois information of a domain, a screen shot if available, what mail servers are defined for the domain, and what IP addresses those mail server hosts resolve to.
The MXServer page shows information for a mail server, which Domains specify this mail server to handle their email, and what IP addresses that mail host resolves to.
The MXIP page shows information for a mail server IP address. On this page you will find all mail server hosts which resolve to this IP address, and all domains which specify a mail server which resolved to this IP.
The SPF page lets you find other Domains with the same SPF rule.
To discover more information on how ReverseMX was designed and built you could check out the blog post here.