> I already have an email address that I want to keep, and having two address will double the spam that I have to delete every day.

The Yahoo! mail account is stored on *their* mail servers. If you don't check the mail there, it simply will be deleted after some days.

Anyway, Yahoo! mail is quite spam-free and they let you configure some preferences about the mail addresses that you consider "junk" (i.e. you can tell their computers to put automatically in the thrash every mail coming from addresses such and such).

Hope this helps,
AP.