|Important||This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here. ArchiveDisclaimer|
This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This page may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.
Defines a function that preprocesses message contents or the format of a message.
Defined function implemented by:
Defined function called by:
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.