Rex is frustrated with email these days. Leo says that email is broken. There's spam, mailing lists, reminders, and more. It makes it very hard to wade through the clutter.
GMail is really the best option in dealing with this challenge. Gmail has a priority inbox, and can sort messages via social tabs, reminders and notifications, and promotions. It also will guess what his primary folders are, and can sort out person to person conversations. He can also drag an email to a preferred folder and gmail will remember where it should go.