P/Invoke C++ function and C++ interface (e.g. MAPILogonEx,GetMsgStoresTable)

Hi!!

I'm beginner programmer and I'm wondering if there is any diffrence between invoking function and interface form c++. As I don't have problems with function (MAPILogonEx), I can't invoke GetMsgStores, which belong to interface IMAPISession.

The error is that it can't find entry point for GetMsgStoresTable.

Here is crucial line, I think:

[DllImport("cemapi.dll")]
public static extern uint GetMsgStoresTable(uint unicodeFlag, out IntPtr messageTable);