Receiving Messages using Hook Providers

The following diagram illustrates the interaction between MAPI components involved in the message receiving process.

The steps in this process are:

1. The underlying messaging system delivers a message to a transport provider.
2. The transport provider communicates with the MAPI spooler to get a pointer to a new message object created by the message store provider.
3. The transport provider writes the inbound message's data to the new message object in the message store.
4. The MAPI spooler calls all hook providers to operate on the message.
5. The hook providers communicate with the message store provider to move the message to a different folder, delete it, and so on.