Here's a summary of the sources of one gmail screen's worth of email. Surprisingly, all of this spam been forwarded via one of my alternative email addresses. (I guess I don't typically give out my gmail address.)
|email address||spam count|
From this sample it would seem I can cut out half my spam by getting off the forwarding list of email address I no longer use. On the other hand, I most often use evan@lj, and that one is the worst...