When I use the "Next Unread Folder" key, KMail does jump to the next folder with unread messages.  However, the specific message that it jumps to is the one which is furthest toward the top of the screen.  This creates a choice of sub-optimal solutions if you sort by date:

1. Sort messages in date-ascending order (so that the newest messages are at the bottom) and deal with the fact that KMail always assumes the most important messages are at the top of the list.  This is what I have historically done and I'm constantly having to scroll message lists around any time I navigate without using the "next/previous unread folder" keys (which, thankfully, is most of the time).

2. Sort messages in date-descending order (newest messages at the top...the default) and have KMail select the newest one, then have to read the messages in reverse chronological order unless I explicitly scroll the index and click on the oldest unread.  This is a larger problem when using threads, since the unread messages usually aren't in a contiguous block at the top.


I think the core of this is a UI issue stemming from the fact that KMail's navigation semantics are all centered around "spatial" navigation.  In other words, when you hit the "Next message" key, you get the next message in list order...not in _sort_ order.  To put it yet another way, when I'm using the default sort (date-descending) and I ask for the "next" message, I get an _older_ message.

As I see it, there are two ways to approach this if it gets accepted:

1) When entering a folder without instructions on which message to select, select the bottom message if the sort order is ascending (or, at least, date-ascending).  For what it's worth, this would be my preferred solution.

2) When entering a folder using "Next Unread Folder", always select the oldest unread message.