If I resize the kmail/kontact window, the current message list gets resized. But instead of simply resizing the width of the "subject" column, which most smart mailers do, kmail/kontact resizes the right-most field, which is "importance" for me. So by maximizing the kmail/kontact window instead of earning much space for the "subject" field, the "importance" field earns half of the screen (which by the way needs only a fixed width).

I didn't find a way to configure this. Not even in the designs editor, where some text suggests me to do a right click on elements to get additional options, but with right clicking anything nothing happens.

Reproducible: Always

Steps to Reproduce:
1. start kmail or kontact
2. resize the application window
3. watch the mail message list while resizing