Spam Filter Service Hiccup

A funny story appeared on Wired News:

While hundreds of thousands of Americans rush to sign up for the Federal Trade Commission’s new do-not-call service, many Yahoo users are left wondering why they haven’t received their registration confirmation. The reason? Yahoo’s spam filter doesn’t like the FTC’s onslaught of e-mail.

It seems that legal spam does exist, but the spam-filers trigger on it. But then maybe I should not call it spam. It shows that you can noyt always define a spam filtering rule which applies to all users.