Distributed Sender Blackhole List Errors (DSBL)

Issue encountered

You are seeing errors in your logs indicating a DNSDomain Name System - Enables the translation of hostnames to IP addresses and provides other domain related information. failure, when checking against list. dsbl.org or unconfirmed.dsbl.org


You are experiencing delays when receiving emails, due to slow response times, or timeouts when querying *.dsbl.org


The Distributed Sender Blackhole List (DSBL) has been taken offline by the owners, due to their belief that the list is obsolete. As a result, all name server queries submitted against the list will fail. You can read more about this at http://dsbl.org


In order to overcome the errors generated by the failed lookups, you can remove the two DSBL entries in the Blacklist setup screen:

  1. Login to the Kerio Connect Administration console
  2. Select: Content Filter > Spam Filter > Blacklists
  3. Highlight the DSBL list and press Remove.
  4. Repeat this for both entries of DSBL.
  5. Click Apply.