"possible spam" not getting quoted

Hello list, I'm back with another puzzle. This time about kmail (the version in 3.5.13.2). I recently changed my ISP and the new one has an option to filter the mails with spamassassin. I am starting to receive more mails that spamassassin forwards with this header: *************************** X-Ham-Report: Spam detection software, running on the system "<my isp>", has  identified this incoming email as possible spam.  The original message  has been attached to this so you can view it (if it isn't spam) or label  similar future email.  If you have any questions, see  root\@localhost for details. *************************** These mails are *not* spam but probably some sort of html/mixed html messages. The good point is that the mail is turned into plain text, the problem is that such mails don't quote the message when replying...... As far as I can say this only happens with such fowareded mails. I'm considering turning off that spam filter (I have spamassassin running localy and I use an external service), but maybe somone understanding kmails internals better than me can give an advice? Regards, Thierry