About 2/3 of all the emails that I sent and received in the last two years were spam or worms (mostly the infamous Swen worm):
andreas@tintifax:~$ ls -l spam swen
-rw------- 1 andreas andreas 956976042 Jan 24 17:58 spam
-rw------- 1 andreas andreas 252381193 Jan 23 21:01 swen
andreas@tintifax:~$
gna