Version:            (using KDE KDE 3.5.0)
Installed from:    SuSE RPMs

Kmail should have an alternate keyboard navigation -- please look at http://bugs.kde.org/show_bug.cgi?id=21256

While someone could argue that current design is nice and etc. I think it is confusing and even in long irritating because it is not like anything else. So I propose as an OPTION alternate navigation -- navigation in selected section _only_. User could choose which sections are selectable /which could get the focus/ -- folders sections, messages, or message body /view/. 

Having such possibilities I would choose as selectable message body and messages. Down-arrow key would always mean next while up-arrow would always mean previous. And I could set focus at messages, press down-up key to get to the interesting message, hit tab key /switch to next selectable section -- in that case: message body/ and still using up-down key read the whole mail.