KMail filters very slow

[Tomas Van Verrewegen]

I just installed spamassassin. Now, when I start KMail, the UI is responsive for about 3 seconds, then, I suppose, new messages are filtered, so the UI blocks until spamassassin completes checking all mails. This sometimes takes up to 1 hour to finish.
I believe the filtering code should run in it's own thread, seperate from the KMail UI thread, so KMail can still be used if the filtering takes a long time.

tomas@tomas:~$ lsb_release -rd
Description: Ubuntu 11.10
Release: 11.10
tomas@tomas:~$ apt-cache policy kmail
kmail:
  Installed: 4:4.7.4+git111222-0ubuntu0.1
  Candidate: 4:4.7.4+git111222-0ubuntu0.1
  Version table:
 *** 4:4.7.4+git111222-0ubuntu0.1 0
        500 http://be.archive.ubuntu.com/ubuntu/ oneiric-updates/main i386 Packages
        100 /var/lib/dpkg/status
     4:4.7.2+git111007-0ubuntu1 0
        500 http://be.archive.ubuntu.com/ubuntu/ oneiric/main i386 Packages