The easiest ways around this is don't use your main ISP email address unless you absolutely have to. Use Hotmail, Yahoo, GMail, etc and if you start getting crap of marketing companies change the address.
It also pays to keep your spam filters up to date with your email provider.
If antis want to spend $2500, a time, on email addresses then I for one encourage them. It'll be less money they have to follow us around.