Kmail + signature

Haia Lately, or maybe it is after updating to SuSe 8.2 , I keep getting those irritating email's ( in Colour) what tells me that I received an email with a signature what could not be verified. Apart of sending them straight away ,without reading, to trash , is there an other way in Kmail to receive and read them just as normal mail? I'm really not interested what other people do to their mail as long as it comes up in normal text on my email program. Thanks for your help. -- Greetings from /bill at 169 west , 19 south. My holy cow is a penguin.