I am also sorry that this has happened to you,
This is one of the things to consider when making the plunge into a shared hosting environment as none are truly immune to this. Tools like http://www.mxtoolbox.com/blacklists.aspx can help you discover if the IP you’re hosted on has been blacklisted on other lists as well. The host’s efforts are necessary when removing a server’s IP from a particular listing but ultimately the time it takes is solely up to the blacklisters and they don’t particularly care if the hosting gods themselves request removal.
Being that this is supposed to be a Q/A.. here’s my A…
From the point of view of many email providers, Backscatter is providing a necessary solution to a spam epidemic that really gained strength around the time that emails seized being text only. In 2008, 76 trillion spam messages were sent to unsuspecting users, according to Royal Pingdom. It accounted for 70 percent of all emails. By 2010, it had skyrocketed to 107 trillion messages – nearly 90 percent of all emails sent.
When it comes down to deciding on a hosting solution for my domains, one thing I weigh is the level of dependence that I have on emails from that domain reaching their destination. If I am going to use the domain for emails and will depend on the domain’s emails reaching their destination, I will most likely decide on a more dedicated IP solution, and this is still not foolproof.
Not everyone uses the same measuring stick tho.