Version: (using KDE KDE 3.4.2) Installed from: SuSE RPMs It appears the filter application behaves correctly when only one message is selected (in this case, in the inbox), but when the entire box is selected (I didn't try other quantities) the application quits responding. My guess is that it repeats the process throughout the selection. I was running the KMail plugin within Kontact. I'm a former Win32 developer but haven't started developing in Linux/KDE yet, but if you'd like me to help diagnose this, please let me know. Thanks
Apply Filters is a blocking operation.
You can force the usage of async filtering (in Apply All Filters) by manually putting "actionscheduler=yes" in the [General] section of kmailrc. Please note, that this functionality is known to produce crashes in KDE 3.5.0, but you might want to give KMail from KDE 3.5.1 a try once it is out.
Is this still a problem in KDE 4.3?