Bug 280125

Version:           4.7 (using KDE 4.7.0) 
OS:                Linux

I use KDE 4.7 with Kmail 4.7. Today I activated spamassassin 3.x (Perl) as a spamfilter via Kmails spam assistant.
 
I know that spamassassin in the Perl version is a relatively slow filter, but it worked very well for the old Kmail 1.x versions.  

However, now it seems that despite appropriate filter settings spamassassin  checks all the mails in the imap folder for incoming mails again after each restart of kmail or even after changes to the filter settings. And this, of course, blocks the use of Kmail for quite a while in case there are many mails in the imap inbox folder. 

In my opinion - after an initial first run - spamassassin should only check new incoming mails. This, however, is not the case. From the progress information one can clearly see that all (!) the mails in the imap inbox folder are checked again immediately after each start of kmail.     

In contrast to spamassassin there is no such behavior for bogo-filter.

Reproducible: Always

Steps to Reproduce:
Start kmail with an online imap inbox folder with many mails and spamassassin (PERL version) activated. 

Actual Results:  
Spamassassin investigates all mails in the inbox folder after a kmail start or a filter change. 

Expected Results:  
The spamassassin filter should only check new incoming mails.