Kmail and GnuPG

Hello everybody! I've just started to use KDE 3.3.1 and I have a particular question regarding Kmail and GnuPG. I cannot find a way to get Kmail to auto retrive keys to verify messages. I have set: "keyserver-options auto-key-retrieve" in gpg.conf but this doesn't help with Kmail. I've had a quick Google for an answer but came up blank. Does anyone know if a) if it's possible and b) what I need to set. Thanks in advance. Mark