Kmail + LDAP question

Hello all, one of my customers is trying to connect mail clients (KDE and evolution) to LDAP, but although they increased the validity timing of nscd daemon cache (improving the performance of LDAP-authenticated services), only evolution had benefits, Kmail is still sending a lot or network requests to the server everytime they change folder, resulting very slow. Is there any Kmail configuration item for this? Is it a known Kmail problem? Thanks for your help Pietro --- What sane person could live in this world and not be crazy? -- Ursula K. LeGuin