I maintain a Yahoo Mail account, even though I never use it for anything. Despite the existence of “SpamGuard,” Yahoo’s spam filter, it still fills up with spam on a regular basis. Every once in awhile, I go through and click on “This is spam” on every message in my in box in hopes of improving their spam filter, but things just don’t seem to be working out. In fact, the spam I get at my Yahoo account is not only the most obvious sort of spam, but also comes from the same people over and over and over. I kind of wonder what sort of spam blocker they’re using — both SpamAssassin and the Mozilla spam filter are working pretty darn well for me, so I have trouble seeing how they could be having such problems. I imagine it is a design consideration of some kind given their user base, but for somebody who gets nothing but spam in their mailbox, it’s very frustrating.