On the December 18, 2006, the DNS blacklist ORDB.org (relays.ordb.org) has been shut down.

Quote from http://www.ordb.org/news/?id=38:

"It's been a case of a long goodbye as very little work has gone into maintaining ORDB for a while. Our volunteer staff has been pre-occupied with other aspects of their lives. In addition, the general consensus within the team is that open relay RBLs are no longer the most effective way of preventing spam from entering your network as spammers have changed tactics in recent years, as have the anti-spam community.”

As of March 25, 2007, ORDB.org started confirming all requests done to the blacklist, which will result in the incorrect blocking of emails.

If you have checks against relays.ordb.org configured in your mail server or spam filtering software (example Lotus Domino), please stop querying the list immediately.