Well, the whole idea is to identify SPAM, not blocking or deleting it. Once the mail has been tagged you may ask your mail application to move it to a folder, delete it or whatever.
Just deleting tagged mail on the server is another possibility but I'd advise against it right out of the box - use tagging combined with a filter in your mail application and evaluate it for a couple of weeks before doing so, just to be sure that you're not loosing any real mails in the process.
Keep an eye on mailinglists as there are quite a few people who join a mailinglist, forget about it (or can't figure out how to get off again) and report it to SpamCop or something similar once the mails start rolling in.
Anders C. Madsen
Golden Planet Support - http://www.goldenplanet.com