Easy, there are are people who sort everything into a system that often no one besides themselves see through and people who use search. I'm absolutely #1 - I've been filing my emails into a set of folders and I usually find everything I need by just looking through one folder (because sometimes you don't know the keyword or the person, just a vague feeling of "I'll notice when I see it"). In my last job we used GMail and the labels just didn't cut it (partly my bad because I didn't set up this elaborate folder structure) and I hated it.
