Long term, it wouldn't be a bad idea to get an E-mail address that isn't tied to your ISP. I use multiple addresses -- a Yahoo one that I pay for (for no ads), and one on a custom domain. I use the Yahoo one for everything but high-priority stuff (as in work related items.) This can be expensive though.
I also use Outlook (not Outlook Express), which gives very good filtering tools. That way, I can get the ISP to just mark spam (rather than outright delete it), and my filters do the rest.