I just did a little experiment. I placed an entry for the ip address of one of my web servers in /etc/hosts (or rather the Windows equivalent of it on my PC) with host name www_host.exam_ple.com. I emailed myself a message containing the text http://www_host.exam_ple.com
When I looked at the message in Thunderbird the URL was a hot link. Clicking on it opened my browser looking at the site at that ip address. Even if there are no host names in the SURBL right now with "_" in them, if SpamAssassin skips over those, just like Justin said spammers will start using them. -- sidney
