mail won't let me in!!

After a series of kernel panic issues, I was advised to reload my OS (I'm on an iMac intel processor running 10.4.8) -- so I did that, I'm downloading all the updates, etc. and I got my mail up and running. But I want to add rules to my messages to filter them into set mailboxes, and when I click on preferences, it doesn't give me any options other than the setting up the accounts.

Any advice? I've done it so often before I think I'm missing something simple.

thanks!

M