Hi List, I have exchange5.5 sp4 at winnt4.0 sp6a running LDAP. I have recently installed IBM Lotsu Sametime conferencing server3.0. I want the users logging on to sametime are authenticated by Exchange server using the LDAP. The sametime server is able to connect to Exchange via LDAP and users are authenticated but sametime says the temporarily unable to verify logon, try again later. Any help ???? Regards, Chand