Oddly enough, almost all of it comes to my school address. The address that I use when I need communication to be vaguely reliable. The address that I've been careful about checking the privacy policies of the few companies I've given it to (companies I've bought things from or through).

The freebe address I use, from Softhome.net (one of the last remaining free providers to include POP3 access), which is also the address I use when registering on random Internet message boards and such, gets maybe 1/10th the spam that my school email does.

Murphy's law at work.