Hi! Additionally: Outlook client tries to connect to Exchange 2003 by using "RPC over HTTP". After that I became the error message: "The bookmark is invalid" Any idea? I found some information in Internet about bookmark error message and installed the newest MDAC (version 2.8). Bit it didn't help me. Does the RPC over HTTP problem depend on the bookmark error? How can I solve the problem? Please help.. Best Regards Mustafa