Here’s 2 good ways to keep spam at bay:
Route your email through Google Mail
1- forward all your mail to a Gmail account that you set up
2- Tell Gmail to forward all your mail to a private email address of yours
I pay $1.95/month for the Cloudmark Desktop service (http://www.cloudmark.com/) and it works very well. I think it costs $4/month for new subscribers or you can use my referal code to get it cheaper (http://www.cloudmark.com/?rc=hze4hl). It’s only for MS Outlook or Outlook Express.