Originally Posted by websissy
How's that again? How is it possible for the server's IP address to be listed as a spam source if all domains on the server are innocent? As is common these days, all domains on the server do share the same IP address.
Some blacklists list whole subnets if one or more IPs from that subnet send out spam. But usually blacklists write something about their policy on their web sites, so maybe you can find out if this is the case.