New bit of info: It appears that *every* URL triggers this. It doesn't matter what the domain.
This makes me think that you are not getting the right answer from http://www.surbl.org/ since according to the BearHTML help it is querying this location for the data. Here are some reasons for the false positives. You are probably not using SpamAssassin but you might be using something that modifies how the DNS queries work.
DNS bugs and incompabilities leading to false positives
There is a bug (#3997) in versions of SpamAssassin older than 3.1
where the responses to DNS queries occasionally get mixed up,
resulting in very rare false positives (wanted mail tagged as unsolicited).
This can be seen when SpamAssassin shows a domain as blacklisted
but it is not blacklisted when checking with a
manual DNS query
or on the
lookup page.
The solution is to upgrade to SpamAssassin version 3.1 or later.
Another issue for some anti-spam or anti-phshing
DNS or proxy services that modify
the results of DNS queries is that some of those changes
may not compatible with SURBL applications. In particular,
modification of NXDOMAIN responses can result in false
positives due to the changed Address bits in the response.
But any modification of the DNS query results can
lead to application errors. The solution is to
not use DNS or
proxy services that modify query results
on your systems running SURBL applications.
Additionally some ISPs such as
Verizon and others
are now modifying some DNS NXDOMAIN responses
in a way that causes what look like false positives on domains
that are not blacklisted. They appear to be doing this to drive search
traffic to other sites, but unfortunately it breaks DNS responses
for SURBLs and other blacklists.
Please check with your ISP if you are seeing DNS responses modified
in this way. Verizon has an opt-out procedure with instructions on switching
to DNS servers that do not change NXDOMAIN responses.
Others such as Charter have opt-out nameservers that reportedly do not support
NXDOMAIN. If so, then none of their nameservers may be compatible.
One solution is to not use their nameservers.
<blockquote>New bit of info: It appears that *every* URL triggers this.&nbsp; It doesn't matter what the domain. </blockquote><p>This makes me think that you are not getting the right answer from http://www.surbl.org/ since according to the BearHTML help it is querying this location for the data.&nbsp; Here are some reasons for the false positives.&nbsp; You are probably not using SpamAssassin but you might be using something that modifies how the DNS queries work.
</p><h2><font face="georgia, palatino, times"><a class="" name="dnsbug"></a>DNS bugs and incompabilities leading to false positives</font></h2>
<font face="georgia, palatino, times">There is a bug (#3997) in versions of SpamAssassin older than 3.1
where the responses to DNS queries occasionally get mixed up,
resulting in very rare false positives (wanted mail tagged as unsolicited).
This can be seen when SpamAssassin shows a domain as blacklisted
but it is not blacklisted when checking with a
<a href="http://www.surbl.org/implementation.html">manual DNS query</a>
or on the
<a href="http://www.rulesemporium.com/cgi-bin/uribl.cgi">lookup page</a>.
The solution is to upgrade to SpamAssassin version 3.1 or later.
</font><p>
<font face="georgia, palatino, times">Another issue for some anti-spam or anti-phshing
<a href="http://www.surbl.org/faq.html#opendns">DNS or proxy services that modify
the results of DNS queries</a> is that some of those changes
may not compatible with SURBL applications. In particular,
modification of NXDOMAIN responses can result in false
positives due to the changed Address bits in the response.
But any modification of the DNS query results can
lead to application errors. The solution is to
<a href="http://www.surbl.org/faq.html#opendns">not use DNS or
proxy services that modify query results</a>
on your systems running SURBL applications.
</font></p><p>
<font face="georgia, palatino, times">Additionally some ISPs such as
<a href="http://www.surbl.org/faq.html#opendns">Verizon and others
are now modifying some DNS NXDOMAIN responses</a>
in a way that causes what look like false positives on domains
that are not blacklisted. They appear to be doing this to drive search
traffic to other sites, but unfortunately it breaks DNS responses
for SURBLs and other blacklists.
Please check with your ISP if you are seeing DNS responses modified
in this way. Verizon has an opt-out procedure with instructions on switching
to DNS servers that do not change NXDOMAIN responses.
Others such as Charter have opt-out nameservers that reportedly do not support
NXDOMAIN. If so, then none of their nameservers may be compatible.
One solution is to not use their nameservers.
</font></p>