First try turning WPBlacklist off. Do all comments still go into moderation? Then it can't be WPBlacklist. Try turning off your other plugins one by one to see which plugin it is that is doing that. You might have several spam plugins - if you do, you have to be aware that sometimes the different spam plugins don't work well together and that you might end up with unforeseen results.
Just because you have WPBlacklist activated, you aren't going to stop receiving spam. However, you can set WPBlacklist to automatically delete the spam instead of sending it into moderation since that way, you don't have to do as much work. However, be aware that you should know what you are doing if you do this since it is possible that even legitimate comments *might* get deleted this way. So, you should probably turn on e-mail notification of automatic deletions as well if you are going to turn on automatic deletions ... at least for a while to make sure that everything is working as it should