This domain is normally used as a "honeypot" and an anti-spam RBL (Realtime Black List) identifying the IP addresses which have sent spam to my server in the past.
In January 2014 I had to migrate my web sites to a new server with very little notice, and I haven't had time to set up the back-end automation for the blacklist again. When I have the time, I plan to build it again from scratch, using some new ideas.