w driver.</P>
<P>
The responsibilities of the Inbox/Outbox system are divided among four different agents:
<IMG SRC="Mailbox4.gif">

</P>
<UL>
<LI>
The application packages outgoing data, and handles incoming data addressed to that application. It provides data in a format acceptable to the transport driver, and receives information in such a format. It generally uses the MailboxSendControl controller to let the user control the sending of messages.</LI>
<LI>
The data driver describes how the information is