This error message appears in the headers of a message when Exim is configured to use RBLs (Realtime Blackhole Lists):
0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked.
See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for
This error appears when the nameservers in the
/etc/resolv.conf file are not permitted to perform DNS lookups to the URIBL servers.
Change the nameservers in the
/etc/resolv.conf file from a public DNS provider (such as OpenDNS or Google) to your local data center's nameservers; if this does not resolve the issue, you may need to use your own recursive DNS servers. You can read how to update the nameservers in
/etc/resolv.conf here: How to edit your server's resolver configuration via WHM or SSH.