Annoyances - Phil's Rambling Rants
I can't debug your email; I never figured out any version of Eudora other than the really really old one that used to be everything I wanted from an email client until one of eGIX's "service upgrades" made it no longer work. I switched to Thunderbird because the "new improved Eudora" (even more "new" and "improved" than what you have) blows chunks.
Your machine really needs more RAM, and a complete scrub and reinstall. It would be like getting a whole new machine, but for a lot less than the new machine costs.