Larry has Yahoo mail and he gets a ton of spam. He can't really delete all of it at once, because sometimes email from friends gets in there. Leo says that if it's any consolation, everyone gets spam. Yahoo is just doing a poor job of filtering it. Leo says that we've lost the battle against spam, and some webmail providers filter it better than others. Google uses a technique called collaborative filtering, where users let them know if an email has slipped pass their filters and it adds to the list. That's why Leo uses GMail, because false positives are very low and the effectiveness is very high. 99% of his email is spam, but he rarely gets any because Google does a great job filtering it.
Leo recommends having Yahoo Mail forward to a Gmail address and Gmail will then filter out all the spam. There are third party services like OnlyMyEmail.com, which will filter his email for about $20 a year. They also have an email for kids service for $10 which would allow him to see what email comes to his kids before they do.