What is an RBL and how did I get on it?
RBL stands for Real-Time Blackhole List. An RBL list is a dynamic list of IP addresses identified as active spammers. RBLs are also called DNSBLs and wikipedia has a really detailed article on them, if you'd like to learn more.
We also have a great Community Site post on blacklists.
If you run into any problems, feel free to reach out to us.