You don't have those emails set up w/a catchall do you? I have several emails with dreamhost, and one, that is not published, that i have had for over a year, received no spam. others, that are published get a little, but only a couple a week.
I would double check and make sure you don't have those emails set up w/the catchall. That I can see getting lots and lots of spam.
Otherwise, there may be other reasons...if you have your email set up on your site as email me ie. mailto:myemailname.mydomain.coma
I started using php on my pages to hide all email addresses from the bots and the like.
I, like you, so DISLIKE spammers...