One of the main features of SpamAssassin, the core spam filtering component in the MDaemon Messaging Server, is the ability to do DNS lookups. One of the available lookups is a query to URIBL which keeps a list of web addresses, or URLs, that are found in the body of SPAM email.
The example below shows what you might see in your spam report when troubleshooting why a spam message is getting through the filters to the local user.
Tue 2014-07-22 01:34:17: * 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE:The query to URIBL was blocked.
Tue 2014-07-22 01:34:17: * See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block
Tue 2014-07-22 01:34:17: * for more information.
Tue 2014-07-22 01:34:17: * [URIs: ccsoftware.ca]
When this happens the first question we always get asked is: Why was the lookup blocked and what does it mean? (ok first two questions!)