With respect to Barracuda Networks and Spamhaus. I expect, but I do not know, that Spamhaus probes on port 25 in order to identify Barracuda Spam and Virus Firewalls and then block their access to their RBL. Many Barracuda customers have been cut off without warning causing them trouble and pain. Barracuda attempted to find a deal that would work for licensing Spamhaus for our products, however, spamhaus's desire for money could not be met without significantly increasing the price to each of our customers. They wanted us to charge the spamhaus feed price to each of our customers. We tried to find an arrangement for a long time. I personally love the work that spamhaus has done. I was disappointed that we could not find an arrangement once they changed into a commercial entity and started charging customers. When they were providing a free service we promoted them strongly, but when they started charging the customers that really used it, we had to part ways. It is a pity. We recommend customers use only Barracuda's Free RBL: "BRBL" and this is now built into the Barracuda Spam and Virus Firewall. http://www.barracudacentral.org/rbl The BRBL is provided at no charge to anyone who wants to use it (even non barracuda customers). The BRBL has a full time staff that answers phone and email to correct any false positives and handle removal requests -- unlike competing services that charge money and who do not provide a staff. We will consider providing data feeds if anyone has interest. We currently provide the BRBL as a free service. We make no claims about it being better or worse than any other RBL. It does use a massive amount of data in order to determine which IP's should be on the list. Others have made claims about its accuracy and say great things about it. Others complain that we unjustly block them, however, 99.9% of the people who are blocked and who contact us find a BOT in their network. Sincerely, Dean Drako CEO Barracuda Networks