Is there a way to use the up and down arrows to go through the list of messages in a folder, or through the list of folders in kMail?

I think you can reconfigure the shortcuts for these actions in menus Settings, entry configure shortcuts.

By default moving through the message list is bound to left and right arrow.

Cheers,
_

I've got it set up so that a right arrow always goes to the next unread message, regardless of which folder it is in - just makes sense to me.

To do so:

right click on toolbar - configure toolbars - select main toolbar <kmail part> - move "Go to the next unread message" to the right part of the window - assign a right arrow

But that is only part of the job as it still won't loop through folders. To get it to do that go on settings - configure kmail - misc - When trying to find unread messages: "Loop in All Folders"!!!

HTH

I use the default shortcut "+" for that.

Cheers,
_

Cheers! That is quite funny, me jumping through all kinds of hoops and then there is this default keyboard shortcut... Nooooooooooooo.......................

Thanks. I will use to left and right arrows, even if the lists are top down. '+' is useful too.