PreprocessMessage

The PreprocessMessage function prototype defines a function that preprocesses message contents or the format of a message.

Quick Info

Header file:	MAPISPI.H
Defined function implemented by:	Transport providers
Defined function called by:	MAPI spooler

HRESULT PreprocessMessage(
  LPVOID lpvSession,                 
  LPMESSAGE lpMessage,               
  LPADRBOOK lpAdrBook,               
  LPMAPIFOLDER lpFolder,             
  LPALLOCATEBUFFER AllocateBuffer,   
  LPALLOCATEMORE AllocateMore,       
  LPFREEBUFFER FreeBuffer,           
  ULONG FAR * lpcOutbound,           
  LPMESSAGE FAR * FAR * lpppMessage,   
  LPADRLIST FAR * lppRecipList       
);

Parameters

lpvSession: [in] Pointer to the session to be used.
lpMessage: [in] Pointer to the message to be preprocessed.
lpAdrBook: [in] Pointer to the address book from which the user should select recipients for the message.
lpFolder: [in, out] Pointer to a folder. On input, the lpFolder parameter points to the folder that contains messages to be preprocessed. On output, lpFolder points to the folder where preprocessed messages have been placed.
lpAllocateBuffer: [in] Pointer to the MAPIAllocateBuffer function, to be used to allocate memory.
lpAllocateMore: [in] Pointer to the MAPIAllocateMore function, to be used to allocate additional memory where required.
lpFreeBuffer: [in] Pointer to the MAPIFreeBuffer function, to be used to free memory.
lpcOutbound: [out] Pointer to the number of messages in the array pointed to by the lpppMessage parameter.
lpppMessage: [out] Pointer to a pointer to an array of pointers to preprocessed or otherwise generated messages.
lppRecipList: [out] Pointer to an optional returned ADRLIST structure, listing preprocessor-detected recipients for which the message is undeliverable. For more information on the contents of this list, see the IMAPISupport::StatusRecips method.

Remarks

A transport-provider message preprocessor can present a progress indicator during message preprocessing. However, it should never present a dialog box requiring user interaction during message preprocessing.

When a preprocessor adds large amounts of data to an outbound message, certain procedures should be followed. This type of message can be stored in a server-based message store, causing the preprocessor to access a remote store, a time-consuming procedure. To avoid having to do so, the preprocessor should have an option that enables it to store data that takes a large amount of space in a local message store and to provide a reference to that local store in the message.

The preprocessor should not release any of the objects originally passed to the PreprocessMessage – based function.

Before the MAPI spooler can call a PreprocessMessage function, the transport provider must have registered the function in a call to the IMAPISupport::RegisterPreprocessor method. After calling a PreprocessMessage function, the spooler cannot continue submitting a message until the function returns.

The MAPI spooler owns the task of submitting messages. This means the original message is never placed in an array of message pointers and that a call to the SubmitMessage methods is never required.