If you have a mbox file with some big emails, kio_mbox could produce 100% cpu load. For the complete discussion, see: http://bugs.kde.org/show_bug.cgi?id=118926 and also http://lists.debian.org/debian-qt-kde/2005/09/msg00268.html I will attach a patch and a ebuild which improves the performance. With my test mbox it now takes only 8 sec instead of 20 sec.
Created attachment 75595 [details, diff] patch to improve the performance
Created attachment 75596 [details] ebuild with patch, for kde-3.5.0 (it should be easy to apply the same patch for KDE-3.4.x)
Thanks, but this is in kdepim-3.5.5 already.