Again, can you access your email via a WebMail interface, i.e. via your web browser? Many ISP's provide that capability even if you download your email to Outlook or Outlook Express.
I was an Earthlink user until a forced change in ISP about 5 months ago. With Earthlink, I used Outlook Express to receive POP mail, but I could also access my mail by going to Earthlink.net and logging onto WebMail. And, Earthlink provided options to control spam BEFORE it got to my computer when I downloaded to Outlook Express.
You should find out whether your ISP offers such features. They may have it, and you're just not aware of it.
And, regarding Outlook, is some junk mail going to Outlook's Junk E-mail folder?