PreprocessMessage

Applies to: Outlook 2013 | Outlook 2016

Defines a function that preprocesses message contents or the format of a message.

Property	Value
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 about the contents of this list, see the IMAPISupport::StatusRecips method.

Return value

S_OK

Message contents were successfully preprocessed.

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.

See also

IAddrBook : IMAPIProp
IMAPIFolder : IMAPIContainer
IMAPISupport : IUnknown