mail spam rabl.nuclearelephant.com is dead

Today some mails did not reached my inbox and were blocked through my postfix spam filter rabl.nuclearelephant.com.
It seems that this rbl is not available since today.

See this info on sourceforge forum page.

Any legacy services that might have been hosted on nuclearelephant.com have been discontinued, in particular rabl.nuclearelephant.com

Solution:

simply remove from your postfix main.cf:
reject_rbl_client rabl.nuclearelephant.com