Version:           1.4.7 (using KDE 3.0.8 (KDE 3.1 beta2))
Installed from:    Gentoo
Compiler:          gcc version 3.2
OS:          Linux (i686) release 2.4.19-gentoo-r7

a bit of a usability issue here:

when using kmail, i always find that no matter which setting i use in the appearence dialog for positioning of the mime tree, it always gets in the way.

the mime tree is fairly narrow, so i wouldn't want it to take up the entire width of kmail, ruling out the last option.

i don't have a gazillion accounts/folders so i opt for a smaller folder bar in favour of a bigger message area, ruling out the options 1 2 and 3.

this leaves me with only option 4 which means the mails area gets resized whenever a mail with a mime attachment is read. because my new mails are at the bottom (and rightly so), the actual mail entry moves when i click on it!

a possible solution would be to allow the mime tree at the left or right side of the message area (but allowing the message area to take the space when not in use, unlike option 3).or perhaps to have it share space (horizontally, not vertically as in option 4) with the mail selection area.

a better all-round solution would probably be to allow all different areas to be docked and split as the user would have them (ala kdevelop/kate). this would certainly suit me.

cheers, 
gav