Please apply the patch in the URL to kdepim-3.4.1, it fixes the kmail systray not updating to the correct count of emails and thus making it useless.
Which patch? There are three attached to that bug, with comments about each one saying it doesn't work and the other one does, and one of them was applied to svn head but not to branch, apparently. I'd rather wait for a kmail committed to backport this and confirm it works in branch... If anyone else wants to take on testing it with 3.4 go ahead ;-)
I think it's just better to wait for 3.4.2, or apply locally if you would prefer.