Now usually spam is evil, annoying and a bloody pain. It does however have rare moments of actual usefulness. On an average day my mailbox seems to be stormed by more than two hundred spam mails from just about every where on the planet. Thanks to server-side filters combined with mozillas learning filters, they all seem to disappear into a consolidated spambox. I can check the box (too look for any false positives), and if the box hasn’t gotten any new mail for more than an hour, something is most likely wrong in my mail setup.