mxORB

mxORB was originally developed as a basic in-house solution to the problem of spam back in January 2002. The first version of the Mail Exchange Open Relay Blocker (mxORB) used queries to a single DNS blacklist to move mail received from open mail relays to the Badmail folder. At this point mxORB did not have any configurable options and did not offer any other features.

Just over one year later, mxORB had developed into a full-featured spam filter, and the first commercial release became available in March 2003. mxORB 1.0 provided email address whitelist and blacklists, and Internet database queries to filter spam from a variety of sources. A configuration tool and online help simplified the use of mxORB and the amount of spam we received was reduced substantially.

mxORB 2.0 was released in November 2003 and added support for multiple Internet databases including DNS and RHS blacklists, along with content and attachment filtering and a greater range of filtering options.

In recent tests mxORB 2.2, the current version of mxORB which adds further spam filtering options, consistently achieved a filtering rate of over 98%, with a false positive rate of less than 1%. A summary of the test results is shown below. We have a policy of constant improvement and innovation that will further improve results with each release.

• 2,473 messages were received over a 12 day test period
• 2,235 messages were spam
• 12 were blocked by the email address blacklist
• 1,787 were blocked by Internet databases (DNS and RHS blacklist queries)
• 39 were blocked by the content filter
• 5 were blocked by the attachment filter
• 355 were blocked by the anti-virus plug-in filters
• 2,198 messages were filtered in total
• 1 message was incorrectly filtered - less than 1% false positive rate
• 2,197 messages were correctly filtered - 98.3% filtering rate

mxORB is developed in the United Kingdom by mxORB Software. We are Microsoft Certified professionals with over 10 years of software development experience.