When I try and blacklist e-mail senders, I now get the following message:

I have apparently reached the maximum number of e-mail senders I can blacklist, and need to delete some addresses before I can add more!
This is rather silly because I will need to remove some addresses I want to blacklist before I can blacklist some more.
Can someone from VM explain this absurdity?
Also, how do you edit the blacklist anyway? Is there a list of blacklisted addresses somewhere and are they in date order so you can remove the oldest? Also, what is the maximum number of addresses it is possible to blacklist?