The IMAPISupport::GetLastError method returns a MAPIERROR structure containing information about the previous support object error.
HRESULT GetLastError(
HRESULT hResult,
ULONG ulFlags,
LPMAPIERROR FAR * lppMAPIError
);
The IMAPISupport::GetLastError method is implemented for all support objects. Callers can provide their users with detailed information about the error by including the data from the MAPIERROR structure in a dialog box.
You can make use of the MAPIERROR structure pointed to by the lppMAPIError parameter, if MAPI supplies one, only if GetLastError returns S_OK. Sometimes MAPI cannot determine what the last error was or has nothing more to report about the error. In this situation, a pointer to NULL is returned in lppMAPIError instead.
For more information about the GetLastError method, see Using Extended Errors.
To release all the memory allocated by MAPI, call the MAPIFreeBuffer function for the returned MAPIERROR structure.