Applies to: Outlook 2013 | Outlook 2016

Describes a GUID structure used to describe an identifier for a MAPI interface.

typedef struct _GUID
  unsigned long Data1;
  unsigned short Data2;
  unsigned short Data3;
  unsigned char Data4[8];


See the GUID structure.


An IID structure is used to uniquely identify a MAPI interface and to associate a particular interface with an object. For example, when a client calls IMAPISession::OpenEntry to open a folder, the client sets the lpInterface parameter to point to an IID representing the IMAPIFolder interface. MAPI defines the IMAPIFolderIID to be IID_IMAPIFolder. IID structures are also used to uniquely identify OLE interfaces.

All of the specific IID structures for the MAPI interfaces are defined in the Mapiguid.h header file.

See also


MAPI Structures