Paul, Robin et al - yes, I am back to good 'ole Netscape 3. The deletion
of preferences (which I didn't know included all e-mail folders!)
happened when I was trying to set up the User Profile Manager - I
checked the box that transferred all preferences to the upgrade - then
when I was setting up users, the stupid thing kept duplicating users - I
was trying to delete the extra ones - a dialog box came up with each one
warning that by deleting the user file, all preferences would be lost,
and did I really want to delete the user files. Hell, yes, I wanted to
get rid of them - I just deleted away. But then it deleted the
preferences not only in the upgrade, but in the old version, too.

I tried ALL the various suggestions that came my way (thanks, BTW) to
see if I could find the files anywhere, but nada. The search was
productive, however, in that I did figure out how to open the cache
folder - and found out that my dear 16 y.o. son has been entertaining
himself while doing "research", and has a good, healthy curiosity about
the opposite sex.

And I did have an old bookmark folder on the desktop that I had saved
months ago, but never upgraded, so at least I have links to a few of my
favorite things.