MAPILogonEx fails in WINDOWS XP Machine

[Dhurvas Rameshbapu]

Unable to logon successfully, when MAPILogonEx is being
called in Windows XP machine. Received
MAPI_E_LOGON_FAILED Error code. The same program works in
Windows 2000/NT machines.

MAPIINIT_0 MAPIINIT= { MAPI_INIT_VERSION,
MAPI_NT_SERVICE} ;

HRESULT hResult = MAPIInitialize(&MAPIINIT);

hResult = MAPILogonEx(NULL, (char *)
szMailProfile , (char *) szMailPassword,
MAPI_NEW_SESSION | MAPI_EXPLICIT_PROFILE |
MAPI_EXTENDED | MAPI_NO_MAIL | MAPI_TIMEOUT_SHORT |
MAPI_NT_SERVICE,
&session);

If any one know the answer, please let me know.

Thanks