I figured out how to make this code work. Problem comes from MDAC 2.6 and SP2 is required. See http://support.microsoft.com/?kbid=273791. But as I expected, there is another problem : I can't modify recordset values. When I try to do so, I get this message : "Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if available. No work was done". This error doesn't occurs on WS2003 (with Exchange 2003). I've tried MSDN resolution procedure at http://support.microsoft.com/default.aspx?scid=kb;en-us;Q269495 without success. However, it explains Exchange is a "special case" but it doesn't give any solution. Can somebody help me ??? Thanks a lot.