I recently installed Thunderbird 3.0.3. Just noticed a suboptimal UI setting: in the upper pane, which lists the e-mails in the current folder, the Date column is about 200px wide. So when I keep the window at 480x600, all I see in a row is:

| tree icon | favourites icon | attachment icon | read icon | junk icon | Date and time, followed by 5cm whitespace | ... | P

Where "P" is the first letter of the name of the sender. And the "..." is actually shown this way, I have no idea which column it is meant to be. But I don't see neither the sender, nor the message subject, which makes scrolling a folder for a certain mail rather pointless. I see these when I maximize the window, actually the columns are then not only bigger, they are arranged in another sequence. But I feel that holding a mail client permanently maximised at 1600x1200 is a waste of screen real estate.

My naive solution attempt was to try to go with the mouse cursor to the right edge of the date column and try to shrink it by moving the cursor left while holding down the left mouse button. Not only is this default behaviour for all resizable columns I've ever encountered in GUIs, the cursor actually turns into a horizontal double-headed arrow. But pulling has no effect at all. I cannot make a wide column narrow, and I cannot make the narrow columns wide. I didn't find anything in the preferences either. So can please somebody explain how to get the columns arranged sensibly?