I used EUDORA too, I think it is great, I’ve got about 50 folders and filters set up on most of them. No trouble finding emails from the past.
First on Windows 2 and now on OS X. The cut and paste was always painful. Always liked content search and filtering. I just upgraded to PowerMail with spamsieve. It only works on OS X Leopard. 20 years of mailboxes converted in 15 minutes. Another half day to update the filters. I've used Eudora for almost twenty years.
Trouble is, as of a couple of years ago . . . it would NOT work with MSN.COM SIGH.
That’s what we’re hooked to, now.