ZippyV wrote:
Have you guys/system admins checked out
spamhaus.org ? If your emailserver has low traffic their service is even free and it stops spam from the source: open proxies, known spam-isp's and zombies.
they are usefull but still a bandaid.
also DNS / RBL works on class C subnets.
so if two mail servers are in one C block you block both of them.
unless they changed it recently.