Platform SDK: MAPI

IMSProvider : IUnknown

The IMSProvider interface provides access to a message store provider through a message store provider object. This message store provider object is returned at provider logon by the message store provider's MSProviderInit entry point function. The message store provider object is primarily used by client applications and the MAPI spooler to open message stores.

Quick Info

Header file:	MAPISPI.H
Exposed by:	Message store provider objects
Implemented by:	Message store providers
Called by:	MAPI and the MAPI spooler
Interface identifier:	IID_IMSProvider
Pointer type:	LPMSPROVIDER

Vtable Order

Shutdown	Closes down a message store provider in an orderly fashion.
Logon	Logs MAPI on to one instance of a message store provider.
SpoolerLogon	Logs the MAPI spooler on to a message store.
CompareStoreIDs	Compares two message store entry identifiers to determine if they refer to the same store object.

Remarks

MAPI uses one message store provider object per session, no matter how many message stores are opened by the store provider. If a second MAPI session logs on to any open stores, MAPI calls MSProviderInit a second time to create a new message store provider object for that session to use.

A message store provider object must contain the following to operate correctly:

An lpMalloc memory-allocation routine pointer for use by all stores opened using this provider object.
The lpfAllocateBuffer, lpfAllocateMore, and lpfFreeBuffer routine pointers to the MAPIAllocateBuffer, MAPIAllocateMore, and MAPIFreeBuffer memory allocation functions.
A linked list of all the stores opened using this provider object and not yet closed.