DECLARE INTEGER MAPIFindNext IN mapi32;
	INTEGER   lhSession,;
	INTEGER   ulUIParam,;
	STRING    lpszMsgType,;
	STRING    lpszSeedMsgID,;
	INTEGER   flFlags,;
	INTEGER   ulReserved,;
	STRING  @ lpszMsgID

flFlags
[in] Bitmask of option flags. The following flags can be set:

MAPI_GUARANTEE_FIFO
...
MAPI_LONG_MSGID
...
MAPI_UNREAD_ONLY
Only unread messages of the specified type should be enumerated. If this flag is not set, MAPIFindNext can return any message of the specified type.

#DEFINE MAPI_UNREAD_ONLY  32